There is virtually no running water in the Yucatán Peninsula because of the karst (limestone-cap) topography with its maze of underground caverns; consequently, most settlements are found near naturally occurring sinkhole wells (Maya: c'ono'ot; Spanish: cenotes). Both the pre-Hispanic city-state and the colonial village or hamlet relied extensively on these cenotes for drinking water, although in the city-states, containment systems for rain water were built as well. Contemporary villages depend on wells dug in the twentieth century or on electronically run potable water systems installed by the Mexican government. The pre-Columbian village often clustered around a cenote, as did the administrative/ceremonial center of the nobility. Farmers and the general populace lived on the outskirts of such centers. Pre-Columbian centers, like contemporary hamlets, were constructed as quadrilaterals, with their four corners marking points aligned with the imagined four corners of the flat Maya earth. This quadripartate form provided a framework for integrating human living space within cosmological conceptions, through ritual activity that fostered human health and prosperity with supernatural assistance. Today, the thousands of communities, often isolated in the scrub brush of the north or the jungle of the south, can be contrasted with the few quasi-urban centers that also have considerable Maya habitation. In most of these, Maya is a lingua franca that many non-Maya must speak out of necessity.