This was a surprisingly interesting place to visit, despite it's out of date style and some rather tired attractions. It's cheap, and is especially educational for children and adults. All of the signage is in Bahasa Indonesia, and so if you are not fluent in the language, then you will probably will spend a little less time here than one day. Some of the many highlights of the park are the exhibits of some of Indonesia's major cultural groups, a collection of many of the major fruit trees, vegetables, herbs, science exhibits, baby animal zoo, a huge water park (bring your swimming costume), minatures of major Indonesian cultural monuments, lots of rides for kids, and some rides for adults. Some of the less than stellar exhibits are the 3D theatre, where the 3D glasses don't seem to work, and a native American exhibit at the end of the Indonesian cultural exhibits. I did not come across any English speaking staff, but I am sure the do exist somewhere in the facility. Don't be put off by the entrance sign, that has the name of other related parks in letters almost as big as the name 'Jawa Timur 1'. There is a regular shuttle (a road 'train') that travels between Jawa Timur 1 and 2. The entrance fee was only IDR 150,000 for Jawa Timur 1 & 2, Eco Green Park and Batu Night Spectacular on a weekend. Opening hours vary from week days to week ends, and the park was not busy when I visited on a Saturday afternoon.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.