Lunar eclipses occur when the Moon enters the Earth's shadow; therefore they can only occur at the time of a full moon. They're visible from anywhere that's in the night-time half of the Earth at the time (weather permitting). Consequently any place on Earth will witness several lunar eclipses per decade.

If part of the Moon is inside the Earth's shadow then we see a partial lunar eclipse. If the entire Moon is inside the shadow then we see a total lunar eclipse. The boundary of the Earth's shadow is indistinct because of the Earth's atmosphere. The atmosphere also directs some sunlight onto the eclipsed Moon, illuminating it with a variety of dim red / orange / yellow colours.
A total lunar eclipse can last for up to 107 minutes and it's preceded and followed by at least an hour of partial lunar eclipse. During a total lunar eclipse you can also see almost as many stars as you would on a moonless night.
Partial and total lunar eclipses are easily seen by eye or binoculars, and (unlike solar eclipses) you don't need any eye protection or filters. Binoculars or telescopes will let you watch the edge of the Earth's shadow passing across the lunar surface, and (sometimes) stars being eclipsed by the eclipsed Moon.

The Earth's shadow (umbra) is also surrounded by a partial shadow zone or penumbra, where part of the Sun is blocked by the Earth. If the Moon is only in this penumbral shadow then we see a penumbral lunar eclipse. Penumbral eclipses are usually difficult to distinguish from an ordinary full moon and so we haven't listed them below.