There is an Intur (no phone) office in the plaza of Altagracia. It is open weekdays from 9am to 1pm and 3 to 5pm. Most of the hotels listed below are good sources of local information, too. A very good tourist website with lots of information on the history of the island, as well as where to sleep and eat, is www.visitaometepe.com.
Ometepe Tours, in front of the ferry dock in San Jorge (tel. 505/2563-4779 in San Jorge or 505/2569-4242 in Moyogalpa), runs an excellent 1-day tour of the island, which leaves San Jorge at 9:30am and arrives back on the mainland by 4:30pm. They also arrange multiday package stays with hotels and transport included. A 1-day tour with a car and driver from San Jorge costs C1,540 for one to four people.
If you decide to trek to the volcanoes, make sure you get a reputable guide (known as a baqueano) outfitted with a radio and first-aid kit. Guide quality and prices can vary, so ask around before you decide. Union Guias de Ometepe (tel. 505/8827-7714; www.ugometepe.com) is a syndicate of 30 local guides that offer full-day and half-day tours of the Island.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.