Fly to this Peruvian city? Nah. How about a days-long journey to the Amazon on a cargo ship?

As the boat glided down the Amazon River, I swung from a hammock and watched the endless jungle pass by. I’d never seen so many shades of green in one place. I had come to witness this rain forest firsthand, and it was already putting on an amazing show.

At 2.3 million square miles, the rain forest is one of the most biologically diverse places on the planet, home to millions of species of plants, animals, and insects, many of which have yet to be identified by scientists.

Thanks in part to the rubber boom of the late 1800s, it’s accessible to visitors through a handful of port towns that dot the edges of a few of the thousands of rivers that weave through the jungle. One of the best of those settlements basing a visit to the Amazon is Iquitos, Peru, which is a city of 400,000 people not far from the headwaters of the great river.

Aside from highway route 103 that runs between it and a smaller port town, there are no roads connecting Iquitos to the outside world. Unless it’s via plane or boat, you’re not going anywhere.

Lima, the capital, is two hours away by plane. There is a daylong speedboat ride from a town accessible by car, but my husband and I decided on a different approach we’d heard about from a German couple we met while traveling elsewhere in South America: a cargo ship.

It sounded so romantic. We’d find a boat with room for us and spend three days drifting along two tributary rivers before meeting up with the world-famous Amazon River. Flanked by wild jungle, we would take in the first sights and sounds at a slow, relaxed pace.

Thankfully, we’re flexible travelers and were on a leisurely schedule, because you can’t book these trips in advance, and schedules are uncertain. Just traveling from the coastal city of Trujillo to Yurimaguas, the river-port town from which cargo ships depart, required a 20-plus-hour bus ride followed by a two-hour ride in a colectivo, essentially a shared taxi.

When my husband and I arrived in Yurimaguas, we went straight to the central market to buy supplies for the cruise: hammocks and mosquito nets; bowls for meals aboard the ship; lots of bottled water; and snacks to get us by should the food look dodgy.

The port was more an area that was a stretch of flat, rutted, and sometimes muddy shoreline abutting the river, with space for a handful of boats. Using slats of wood as ramps, men carried watermelons, bags of rice, furniture, electronics, and live animals onto two docked cargo ships.

The Kiara I could take us as passengers. The Eduardo VIII docked next door was full — with two decks of live chickens.

We slipped onto the Kiara I and strung our hammocks between rusty holes in the ceiling of the open-air deck at the stern of the boat.

And then we waited.

We found that while the ships regularly allow travelers passage for a fee — we paid the equivalent of about $30 apiece, which included meals — the cargo is the priority and 200-foot-long vessel would leave only when the it was full.

That, however, was a difficult thing to determine — we had been warned that it could take a few days to embark. So when we wanted to leave the ship for meals before departure, we always checked to see how much cargo was waiting to be loaded or how much space was left to be filled.

To pass the time, I chatted with our hammock-mates. About 40 of the roughly 50 passengers were locals, with the rest international travelers like us. Through my conversational Spanish, I learned that some of the locals were related to the crew and others were going between towns after doing business or visiting family.

Simply sitting on the docked ship was surprisingly enjoyable. At one point, a pod of dolphins splashed around for a few hours. Some were the pink dolphins that are famous in the Amazon. The nearby chicken boat provided great entertainment, including as several chickens, one by one, jumped overboard. They bobbed away with the current, prompting both cheers for the birds that were making a bid for freedom and a debate about whether chickens could swim.

By the time we finally left, we had spent 36 hours — including two nights — on the docked ship. Once we got going, the gentle, warm breeze and the sights and sounds of the Amazon made for a tranquil experience. Over the low rumble of the ship’s engine, I heard a choir of birds chirping and crickets screeching. Vines on trees were so dense that there was no way to see much beyond the water’s edge.

Every so often, thatched houses on stilts interrupted the green of the forest. As the boat slowly passed, I saw into the lives of those who called the Amazon home: a young woman washing clothes, boys playing soccer in a field, young men loading bananas onto a long wooden boat.

The rivers we traveled were a milky brown color from sediment. Too, pieces of garbage floated past, and some crew members tossed trash into the water. I watched one struggle to re-secure a tarp draped over some cargo and then throw the tarp overboard a few minutes later, seemingly out of frustration.

The accommodations — which included the option of a few cabins, though everyone chose hammock space given the heat — were about what you’d expect from this breed of cargo ship. Water pooled in parts of the rusty deck; spiders came out in droves at night. A fat, several-inch-long black beetle sent me running (before a Peruvian girl, no more than 5 years old, picked it up and moved it away from me without flinching).

The bathrooms were awful, the floor covered with an inch of standing water, the toilet with no seat and no running water. We used a bucket filled from a pipe hanging from the ceiling to wash waste away. The pipe doubled as a shower, which I couldn’t bring myself to try, instead using baby wipes every day. Even so, I was grimy.

OK, maybe this trip wasn’t as romantic as I’d envisioned.

But meals were tastier than I expected. One lunch consisted of chicken, rice, and potatoes; another was essentially the same ingredients but in soup form. For dinner, we were served a sweet, cinnamon-flavored milky soup with bits of rice. (If you closed your eyes and imagined a mug instead of a bowl, it would have made a decent after-dinner by-the-fire beverage.) For breakfast, we were served chicken soup one morning and the milk soup another.

Between watching the scenery go by and chatting with other passengers, I also filled the days lying in my hammock reading. Each night on board, the international passengers crowded around a small headlamp and played various games. I had packed a small bottle of rum, which got passed around, and that, along with some translation-induced hilarity, had us laughing into the night.

By the end of the second day, our ship reached Nauta, the small town that connects to Iquitos by road. Here, a lot of locals got off. A bus to Iquitos would take only two hours, rather than the eight hours left to travel on the river. After four days without showering, I found the idea of getting to our destination quicker pretty appealing, but, after buying some beer and snacks, all the international travelers got back on board and gathered on the topmost deck above the wheelhouse. We just weren’t done with our journey.

Surrounded by strangers turned friends, I watched as the blue sky faded to oranges and pinks that deepened as the sun set. A feeling of contentment washed over me. I had grown to appreciate how time seemed to move differently on the boat. I could enjoy the smallest moments and simplest observations because we had nowhere else to be and nothing else competing for our attention.

This pace allowed me to really get to know my neighbors. Everyone on the Kiara I came from different walks of life, but on the ship, we were equals. We were confined to the same space, ate the same meals at the same time, and suffered through the same mosquito-filled heat together.

For this trip, the slow boat was the better option.