Hi karlo, welcome to WAB.
Sounds like you've got a bit of tricky situation there. Raised ponds certainly have value for the wildlife that can reach them, i.e. birds, insects, the larger and more agile mammals etc., but if you want frogs, you will have to ensure there is access to the pond from ground level. This isn't the easiest thing to do, as it needs to be rather more than just a plank (or whatever) leant against the side of the structure. Ideally, you would build an earth bank along one side of the pool, and plant it to provide cover and shelter, but this takes up space you might not have.
Some photos would be very helpful. To upload photos, click on "
Gallery" at the top of the page. On the next page, click on "upload photos" (top right). Choose "Image Library" on the next page. On the upload page, choose category "Forum Images", then browse to find your photos on your PC. When your pics are uploaded, open the message you want to post, then open the photos in a separate tab, copy the "Forum Image" code for each one, and paste into your message.
Hope this helps, looking forward to seeing them.
T2