San Juan del Norte has a storied history (of which surprisingly little remains, besides an old cemetery) and is thus known under its old name "Greytown" and under the name "San Juan del Norte". The town draws visitors mostly for the nature and the excellent fishing in close proximity. Reportedly even president Ortega goes fishing in San Juan del Norte from time to time. To get from Greytown to El Castillo there are two types of boat: slow and fast. The fast boat is a bit more expensive and a bumpier (not to mention wetter) ride and might not be available in the dry season (roughly November to May) when the water runs low. The entire trip all the way to San Carlos can be done in a single day, but then you would miss the beautiful eponymous castle of El Castillo. Along this stretch the Rio San Juan is the border with Costa Rica, but belongs to Nicaragua in its entirety. You will see a road on the Tico side that has been built causing tensions between the two countries. At the north of the river there's the Indio Maíz Biological Reserve reportedly featuring a higher number in species of trees, birds, and insects than all of Europe. It is a good place for seeing different kinds of monkeys and poison dart frogs, among others. The reserve is usually visited from El Castillo.

There are several departures daily both by slower and faster boats. You can be dropped off at various points along the route (just tell the operator of the boat beforehand) and in fact some hotels even have their own pier and the boat can drop you off basically at their doorstep. The main draw of this part is the jungle that can be accessed from El Castillo but also from several smaller hamlets and private reserves along the river. If you are doing this trip west to east, San Carlos is your last chance to stock up on essentials and also the last place with an ATM. El Castillo is a rather small place (there are no cars, for instance) and besides the eponymous fortress (and a butterfly farm "Mariposario"), there is not all that much to the town of El Castillo as such.

San Carlos has always been less a place where travelers stay and more a place where they pass through on their way from or to somewhere else. However, it also serves as an ideal place to stock up on essentials before heading east as well as a place to check emails or social media one last time with reliable internet. That being said, San Carlos has superb views of lake Nicaragua and if you can, you should definitely take in a sundown at the malecon (lakefront). San Carlos also has remains of an old Spanish fortress that while not all that impressive does give a good view of the town, the lake and the river.

While the Solentiname islands were not part of the 19th-century route, they offer attractions in their own right. From San Carlos there are public boats to a number of the islands, but you can always ask around if somebody is going anyway and hitch a ride on their boat. There is no scheduled onward transport from any of these islands, so you will have to head back to San Carlos to continue your trip. Solentiname are very tranquil islands (until the mid-2010s, running water and electricity were unique selling points of pricier accommodation) and they are famous for being the retreat of Ernesto Cardenal, a famous Liberation Theology proponent, priest, poet and erstwhile politician in the Sandinista administration of the 1980s. The other big draw of the island is the painting and balsa wood figures that are produced there, but can now be bought in most parts of the country.

While the travelers of the mid-19th century usually bypassed Ometepe and only saw it from the boat, you are likely to at least stop there (in the port of the town of Altagracia) on the way to Granada if you take the public boat. (The Altagracia stop is sometimes cancelled, however, due to weather conditions).

Leaving the boat and spending a few days on the island comes highly recommended as the relaxed atmosphere and (almost) untouched nature of the volcanoes is truly a sight to behold and explore. Altagracia's harbor is a bit out of the settlement and as you arrive at night, having someone to pick you up may be a good idea. Hotel owners often meet the boat and offer you a ride to their hotel provided that you choose to stay there. There are a few taxis, but they can become full quickly.

It is also possible to fly from San Juan del Norte (SJN) or San Carlos (SCA) to Ometepe's only airport (OMT), which is located near Moyogalpa. The service is provided by La Costeña; as of 2016, their planes fly this route twice a week.

While Granada is not part of the 19th-century itinerary, it is a beautiful colonial town that is worth one or two day's visit. If you want to skip Ometepe altogether, getting to Granada is easy, as the boat from San Carlos simply goes on to Granada after about one hour in port. The trip to Granada takes about three hours and you arrive a bit out of town, from where you could walk or take a taxi downtown. After you have had enough of Granada you can either take the bus to Rivas or go back to Altagracia and continue from there.

While Altagracia is only served by the San Carlos to Granada boat, frequent ferry service connects Ometepe's two other ports (Moyogalpa and San José del Sur) with San Jorge (the port of Rivas).

A fairly straightforward bus ride (several departures daily, roughly 1 hour travel time to San José del Sur or 2 hours to Moyogalpa) takes you to one of these two ports. The locally preferred mode of private transport on the island isn't the car but rather horses or motorcycles and you can certainly rent either. Returning them at another point than you rented them can prove complicated, however. It is certainly possible, however, to bring your own motorcycle or bicycle on a ferry to one of Ometepe's ports and to take it out of the island from another port.

A boat (roughly 45 minutes to an hour travel time) gets you across the narrow stretch of water to San Jorge, the port of Rivas. In San Jorge itself there isn't all that much to see or do, so you should take a taxi (there are no buses and it's too far to comfortably walk) on to Rivas. The ferry can also carry a car (with plenty of advance notice). They should be able to accommodate a horse as well, though whether they are willing to do it can only be guessed. As the locals have gotten horses onto the island somehow there will possibly be a way, but you may draw funny stares, as "Cheles" (the Nicaraguan word for foreigners and white people) don't usually use horses for utilitarian purposes (the locals very much do, all across the country).

The original 19th-century route makes landfall a couple of kilometers south from where the harbor is today, to cut down on the overland distance. However, there is hardly any evidence of this history in the hamlet of "La Virgen de Rivas" (which belongs to Rivas as does San Jorge).

Rivas is not entirely ugly and is actually quite nice, but it doesn't compare to the beauty of Granada or León, and as it doesn't have a beach of any kind few tourists decide to stay longer than absolutely necessary. From Rivas you can take a bus (or if you must a horse or carriage, though that would certainly be both more expensive and difficult to organize) to surfer's paradise and endpoint of this itinerary, San Juan del Sur.

Nicaragua is considerably safer in terms of criminal activity than its neighbors to the north and on about the same level of safety as Costa Rica. Most crime in the country happens in Managua, which is not part of this itinerary. In places like San Carlos or Rivas, however, taking taxis at night is safer, as it is when off the beaten track in or around San Juan del Sur.

Both the Rio San Juan and lake Nicaragua have bull sharks (scientific name: Carcharhinus leucas) a species of shark that can survive in both salty and fresh water. Although they are known to attack humans and some attacks have even resulted in fatalities, rigorous hunting has almost exterminated them in Nicaragua, so probably humans are a bigger danger to them than the other way round. That being said, holding a bleeding hand out of the boat is never a good idea. The river also sees several species of caiman and alligator, that while theoretically able to hurt humans usually confine themselves to eating fish. However, they are a good reason to take a camera with you. The deadliest animals are actually those you wouldn't think of: mosquitoes and dogs. Mosquitoes can cause malaria and dengue, and both diseases are endemic to the area east of San Carlos, with a big nationwide dengue outbreak having last occurred in 2014. Dogs are dangerous because they can become aggressive and aren't 100% rabies free. Should you get bitten by any animal, particularly a dog, seek medical attention immediately. Getting a rabies shot before you go to Nicaragua is a good idea in any case.