Redwood Creek runs along the main path which leads to Cathedral Grove. Bridges cross the creek at four different points. If you're lucky, you can find a quiet spot along the creek or in some semi secluded corner and enjoy the peacefulness of these woods.
Muir Woods is a very easy to explore place. It has a well marked trail which circumnavigates the main part of the park. Even a short visit here can be enjoyable, although there are crowds to contend with. Take a brief walk beneath the giant redwoods and enjoy the cool air of the forest canopy.
You will find a few felled redwoods while touring the main path. Most fall over due to disease or a rare lightning strike. This tree had been tilting over due to some malady when the forest service made the decision to cut it down. A portion of the park was closed while the tree was upright because of the fear that it may crash at any time.
Generally, you can determine the age of a tree by counting the number of rings. The bark of this felled redwood experienced quite a bit of decay, which would make it almost impossible to count the rings. That is, assuming that you would want to spend your time doing that.
But the tree is placed here to show how wide in diameter the redwoods are. Given the average height of over 300 feet, the trunk isn't all that porportionate. Yet, through a system of roots, it is able to support the tree as it continues to grow.
This photo gives a better impression of how large these trees actually are. Although hearing that the redwoods grow to a height of more than 300 feet tells you something, its a different story when you actually see how small the people look in comparison to the towering trees above them.