As you follow the twisting Macal River upstream (south) from San Ignacio [1], you find an astonishing assortment of mid- to upscale lodges, beginning with the San Ignacio Resort Hotel, which is within the city limits of San Ignacio. They are all small properties, some with as few as two cabins in the forest, others with a dozen or more thatch-roof bungalows under the trees and along the river.
Most of the accommodations are small, off the grid, and feel utterly remote, even when they are only a few miles as the crow flies from San Ignacio. They all specialize in arranging tours to area activities, and most offer multiday packages.
Links:
[1] http://www.moon.com/destinations/belize/cayo-district/san-ignacio