How to raise Park Value?

[YaBu]

So I tried building more rides, attracting more guests and having more cash but it seems doesn't affected the Park Value...?

[Inky_D]

make sure the guest are happy and that your rides and stalls are making a positive profit and not a negative one.

[Brickfrog]

Ive heard that putting scenic objects near your rides makes them more enjoyable, things like trees, and what not.

[DRY411S]

Park value is directly linked to the amount you spend on rides and scenery.

Stop spending cash or have no cash to spend, and watch your park value decline.
The Park Value declines as the rides and scenery get old. Replace a ride with one exactly the same and watch the Park Value go up.
Park Value is also linked to Park Rating. If your rating is low, increase that to increase the PArk Value too.

There is a great archive of RCT articles (some of which I wrote almost 15 years ago, which is a scary thought) at this link:

http://www.rctstationarchive.com/knowledgebase/index.shtml