Poptún’s wonderful setting at a comfortably higher altitude and its pine-studded, karst landscape make exploring this part of Guatemala a delight. You can choose from, among others, treks to remote Mayan sites, jungle hikes, caving, or tubing down lazy stretches of jungle river.

All of these activities can be arranged at area lodges, particularly Finca Ixobel (on the road from Río Dulce, tel. 5892-3188, www.fincaixobel.com), which pioneered ecotourism in this neck of the woods and is always on the lookout for new offerings.

You can choose from a number of caves, which can take two hours, a half day, or a full day of exploring. The full-day trip takes you to Cueva del Río ($10), an underground river with rapids and waterfalls where you can swim and leap into the river in total darkness.

There are also trips twice a day to Ixobel Cave ($5), with its rim stone walls, stalactites, and stalagmites a 45-minute walk from the farm. Just 25 minutes’ walk from Finca Ixobel, Echoing Cave ($5) offers a fun adventure exploring the cave’s hidden chambers and caverns, and it is a good option if you have only two hours’ time.

Horseback riding is also available at the Finca Ixobel with trips lasting as little as two hours or as much as two days ($53). A full day of horseback riding costs $23.

Finca Ixobel also runs a number of excellent multiday jungle adventures lasting a minimum of three days and costing $30 per person per day, with a two-person minimum. The treks take you to remote Mayan sites such as Ixcún, a replica of the the caves of Naj Tunich, and waterfalls on the Río Mopán. All trips are on horseback.

Inner tubing on the Machaquilá River from Finca Ixobel ($20, including lunch and transportation) is possible in June and July, when the water is high enough but before the summer rains are in full swing.

Villa de los Castellanos (tel. 7927-7541), another local lodge, is set right beside the river and also offers inner tubing. Trips to the remote ruins and forest reserve of Machaquilá are also available from here, as well as to the Chiquibul Forest Reserve, farther north.

Cocay Camping (tel. 7927-7024, $5 per person) is set in splendid isolation on the banks of the Río Machaquilá just past the town proper. There are camping spaces, very basic cabins, and a café serving vegetarian fare.