The Merced Grove of the Giant Sequoias is the smallest of the three giant sequoia groves in Yosemite. There are about twenty mature sequoia trees in the grove. Sequoia trees are some of the oldest living things on the Earth. Although Giant Sequoias do not get as tall as their relatives, the Coast Redwoods, they are more massive.
What makes this grove so special is its seclusion. Being the smallest grove with the smallest parking lot means you will likely not have too many other tourists in the grove with you. In the other groves, the Mariposa and the Tuolumne, the park service has had to fence off the trees from all the foot traffic, making it difficult to get close to a sequoia tree. That is not the case in the Merced Grove. All the trees grow fence free (at the time of this writing).