Seibal is located close to the small town of Sayaxche, about 62km (38 miles) from Flores, a 1.5-hour trip. There are two rustic ecolodges (and some very basic hotels) in the working port on the Río Pasión, making this a good base for visits to Ceibal and other nearby archaeological sites. Day trips are also easily arranged from Flores.
From Sayaxche, you can make the 17km (11-mile) trip to the ruins by public bus, though you may need to catch a pickup truck for the last few kilometers. Consider spending a few extra dollars to make the trip by boat, a lovely 45-minute trip up La Pasión River. There are no restaurants, shops, or hotels, so pack water and snacks.