The ruins and trees are aquarium decorations, mainly Europet Bernina and Rosewood. The crates are by Pegasus Hobbies. The river sections I picked up on eBay from a seller called Small Terrain.
The detail on the aquarium decorations is great and they have the added benefit that being made for fish tanks they are pretty durable (made of polyresin, I believe).
By swapping the Angkor Wat style ruins for a Greek one it turns into something perfect for 7th Voyage. I'm looking forward to adding the Ancient Cobra statues I recently picked up and getting my Aeetes and Circe cast into action. Again, the Greek ruin is a Europet Bernina aquarium decoration.
Below: The Society of Thule sacking the Tomb of Alexander. Fortunately, Lord Curr was on the case and stopped the dastardly Baron!
I wonder if the aquarium decor manufacturer's realise their stuff is so popular with wargamers?