constellation is famous among astronomy amateurs because of the largest globular cluster that can be seen in the northern hemisphere. It is M13 and contains about 300 000 stars and is about 25000 light years away. This globular cluster is composed of some of the oldest stars in the Universe, they are estimated to be 14 billion years old. Near its core the stars are about 500 more concentrated than in the neighbourhood of the Sun.
In the same constellation there is M92 globular cluster, places about 26000 light years away.
Here is original Messier's description of M92:
"March 18, 1781
`Nebula, fine, distinct, and very bright, between the knee and the left leg of Hercules, it can be seen very well in a telescope of one foot. It contains no star; the center is clear and brilliant, surrounded by nebulosity and [it] resembles the nucleus of a large Comet: its brightness, its size, approach much that of the nebula which is in the girdle of Hercules. See No. 13 of this Catalog: its position has been determined, by direct comparison with the star Sigma Herculis, fourth magnitude: the nebula and the star are on the same parallel.' (diam. 5')"
M92 photo was taken as RGB with 30 minutes total exposure for each channel unbinned during Full Moon :) M13 photo was 30 minutes each RGB and additionally 90 minutes luminocity.