Tanah Lot Temple is located approximately 40kms from the middle of Seminyak and will cost you between IDR300,000 and IDR10,000 depending on how good you are at bargaining prices with cab drivers. Once you arrive, you will have to fight the hordes of people; locals and tourists, trying to visit the religious site. Beware of being ripped off at the tourist traps such as the many, many souvenir stalls and the photo-ops with a local python or two.
The temple itself is located on a rock formation that is off the shore and surrounded by water. It is said that the site dates back to the 15th century and is a very important part of Balinese religious and mythological history, hence the popularity with pilgrims from all over the world.
Although this place is incredibly busy at any hour of the day, as with many ocean side attractions, the most popular time is late afternoon just before sunset. At low tide you can walk across the dark coloured slate like rocks to get to the base of the temple. To be blessed at the site, it will only cost you a small donation which will go towards funding the restoration of the temple. If you do decide to go late in the day, please leave at least an hour to make your way back to Seminyak or Kuta as the roads will be bumper to bumper traffic by this stage.
Admission tickets will set you back about IDR15,000 and you can buy them from the site office as you enter from the carpark. If you are driving it costs IDR5,000 to leave your vehicle outside during your visit.