Hovenweep National Monument is located southeast of Blanding, Utah, and west of Cortez, Colorado on the border of the two states. The monument itself is in Utah, but some of its outlying ruins groups are in Colorado, others are further in to Utah, while one straddles the border.
The uniqueness of Hovenweep lies in its towers, square as well as round. The exact uses are not agreed upon- archaeologists posit such uses as defense, astronomical observation, signalling, as a conspicuous show of power, and simply as a local trend in building. The true use of the towers is likely found in a combination of many of these theories.
The National Monument has a recently upgraded visitor's center, well-kept campgrounds, and easily walked interpretive trails. There is a water hydrant in the parking lot. Beyond the Monument proper, at the outlying groups, as well as off in the desert where there are countless other ruins, one could spend weeks exploring.
The outlying groups are definitely worth visiting. You may or may not be able to get information from the rangers at the Monument about other ruins in the area. There is plenty of camping all around the Monument if you do not want to camp in the campground. Most of the land adjacent is BLM, although to the south you will find Navajo and Ute land that is off limits.
The ruin in the photo to the right was found in a canyon near Hovenweep National Monument. This is an example of what you might find exploring the nearby canyons.