This cache is located in an interesting, yet somewhat eerie, abandoned site.
Taman Festival Bali was a sprawling 10-hectare entertainment complex and amusement park with lazer light show, 3D cinema, exotic animal exhibits including a small island "Crocodile Rock" surrounded by a moat full of crocodiles, and at its heart, a man-made volcano which shot fireworks as lava from its mouth. The park opened in 1997 and was abandoned shortly thereafter during the height of the Asian Financial Crisis, leaving the buildings, grounds, and animals on-site to their own devices.
These days nature is reclaiming the site and it creates a beautiful, yet somewhat eerie scene. It has become a canvas for street art by artists from all over the globe with some very impressive graffiti. Most interestingly, the jungle is absorbing the buildings and overgrowing the entire area. Because of this, you may find that it is not as simple as going from A to B (or parking to cache, as it were) - you will have to navigate the jungly maze that this place has become over the years in order to find the GZ, then navigate the additional challenge that the jungle creates for the hide itself! You will see from the attributes that you are looking at a hike of over 1 km but less than 10. The hiding spot is not visible to the naked eye and presents a substantial challenge - don't forget your GPS signal may be weakened by the thick canopy of trees growing overhead. The cache container is small and contains only a log book, so BRING YOUR OWN PENCIL! It will be very satisfying to sign this log once you actually find the cache :)
You can easily spend a few hours exploring this poetic site. Taman Festival is frequented by photographers trying to capture the unique atmosphere and eerie vibe.
Wear shoes, proper clothing and bring your own drink or snack. Maybe breadcrumbs so you can find your way back through the maze ;) Even though the place is abandoned and not being kept up, there is often a security guard near the parking that will try to charge you a minimum 'donation' of 10,000 IDR to enter. This is not necessary, and can be avoided by using the alternate access and parking coordinates. Be wary of where you place your feet as there are many pieces of glass, rusted nails, debris, and crumbling cement and tile, though mosquitos are probably the most dangerous thing about the site these days... Bring bug repellant! Use common sense and Enjoy!
Happy Caching!
Edit: Updated terrain based on input - as quoted from geocaching help centre: "Extremely demanding movement over potentially hazardous terrain."