Walking over or across a threshold to the spirit world, paired with achieving an alpha state of consciousness, is another technique to join the spirit realm. Physically, you may achieve this by entering a graveyard or sitting at a crossroads and exposing your mind and senses to the ghosts surrounding you. Mentally, you might think about someone who has died (this person can be either good or evil), believe you have left your body, and hope that you will be given permission to enter their world. In some cultures, people believe that there are certain places where the veil between our world and the next is thin. These places include church graveyards, especially old ones; mountainsides; near standing water such as lakes or oceans; under large trees; and even more recently developed areas such as city parks. When you go into these special places, you should try to be aware of your surroundings and accept that things may not be what they seem. For example, if you see bones lying on the ground, there could be something sinister going on but you would never know unless you went beyond just looking at the physical remains. People also leave markers to indicate that they have entered a special place. This may be done intentionally, by carving words in a stone with a knife as a form of warning for others to keep out.