The Río Bec archaeological site, the namesake of this region, is made up several scattered groups, and is currently being excavated. The architecture follows the region’s dominate style, with high steep towers and tight-fitting stonework, but a lack of a central plaza and no evidence of a larger settlement suggest Río Bec was a getaway of sorts for the elite. Each group of structures may have functioned like a colonial-era hacienda, occupied by a privileged family and a small staff.
Unfortunately, Río Bec is quite difficult to visit. You must have permission to enter the area, and the access road is rutted and overgrown; after a rain, it can be impossible to pass. The proprietors of Río Bec Dreams (Carr. Escárcega-Chetumal Km. 142, tel. 983/124-0501, www.riobecdreams.com [1]) in Xpujil [2] can arrange a tour of Río Bec, but plenty of advance notice is required.
Links:
[1] http://www.riobecdreams.com
[2] http://www.moon.com/destinations/cancun-the-yucatan/the-state-campeche/rio-bec-region/xpujil-town-and-around