Why do we visit cemeteries? Mortality is a rough deal. We go through a lifetime of high's and low's only to end up in the gutter. Some premature others after a long (insert everything is relative here) life. After that ordeal, many loved ones choose to select a location that some frequent in their next stages of life.
The earliest recorded cemetery is Taforalt, a cave found in Northern Oujda, Morocco. We haven't been able to discover evidence of how this cemetery was used, perhaps in the same way we use them today.
We don't match Cemeteries by religion, it's something that has existed long before modern-day religion, and today even atheists still bury their dead.
Similar to all other rituals, a visit to the cemetery is about a spiritual bond that we wish to keep. Some tour to enjoy the silence, others to pay respect to their loved ones and others to get a thrill. All of these reasons are in some way, a mechanism that connects us to something greater and gives us comfort or even discomfort.
Our father/father-in-law has a unique ritual of his own. Every morning on December 25 he drives 136 miles to visit a cemetery. He does this regardless of the weather. If you have ever been to Denmark during winter, you'll know that this is quite the feat. He drives there to visit his father in law who passed away almost two decades ago. He does this to pay his respects and to continue the strong bond they managed to create together. Somehow it gives him peace as he's always in a good mood when he gets back.