While nearly anywhere on the physical plane can be an exceptional place from which witches can draw power, non is more potent then that of a cemetery. While they typically only associated with burial rights for the dearly departed, they serve as a great hub for witches to perform various magickal operations.
Witches are connected to the the physical, the spiritual, and the divine, and graveyards are a place where all three world actually connect. The tombs and monuments act like cell phone towers that helps witches focus their energy so that they can access the spirit world as well as divine energies which is why it is considered a place of power. I had to do my right of dedication in a graveyard. I was nervous as hell, being only 16 years old at the time and naked, but my parents said to have faith in my magick to protect it and it will. And it totally did! I was not interrupted by security.
In graveyards, the veil is thin, power flows much more freely into our world from the ethereal, and as a place where the living and the dead actually meet, graveyards allow witches to strengthen the connection to their ancestors and guiding spirits. They hold a plethora of paranormal energies which witches can channel and untlize for to add additional power to their spells.
However, one also needs to remember that graveyards are a place that some spirits call home, and needs to be treated as such. Cemetery spirits are in charge in these places of power, and without first building a rapport with its inhabitants, they can really mess up the integrity of your spell. Think of this way, what if someone just randomly came into your unannounced and just started setting up candles and casting a circle? You’d probably be like “umm excuse me, WTF?” Same principle applies here, so before doing any kind of magickal working within the gates of a graveyard, there are a few things one must do in order to get permission and possibly even help from the spirits who call it home.
Firstly, you must visit the cemetery at least 2 or 3 times before preforming and magick there. Walk around, sit on a bench and meditate to talk to the spiritual inhabitants. If you feel drawn to a specific grave, go to it and sit by it, have a chat with whoever might be sitting next to you.
Always cleanse yourself before and after entering a cemetery or any place where spirits call home, doing this will prevent any attachments. Also always enter these places wearing a hood (you can take it off once inside). Always also try to bring an offering, like flowers, tobacco, alcohol, or food, to leave at the gate or on a bench as a show of respect to the spirits there. As I mentioned, these places can be powerful for spell work but be sure to respect the entities that call it home or else they can weigh down the energies of your casting. Conversely, if you build a relationship with these entities prior to your spell work, they may allow you to channel them for extra energies during your casting.
Please let me know if you have any questions, and be safe! 😉