Mount Marcy is the highest point in the state of New York. The summit sits at 5,343, providing you with amazing views...which takes about ~7hrs. in total.
The hike does offer several different terrains and an elevation gain of 3170 feet, which can make you feel like it's going to be a long day. There are four routes for summiting Mount Marcy. This is the most popular route and leaves from the Adirondak Loj. Once you hit the trail, you will head up toward Marcy Dam, which if you're not camping at the Loj, makes for a good place to set up a base camp. Continuing on the trail, you'll get the heart rate up on a steep ascent to Indian Falls. The elevation gain calms a bit once you reach the falls and head to the tree line -- keep an eye out for changing weather as you start to head above the tree line.
Once you reach the summit, enjoy the views!