The sandstone boulder is an interactive piece of scenery located in the Imperial district of Menaphos. After speaking with Zahra and paying her 12 acadia logs, it can be mined to build a cactus patch which is disease-free after completion of the hard desert tasks.
The boulder is mined in two stages - first into a few large chunks, and then into small pieces. Each swing yields Mining experience, scaling to the player's level. Every attempt is successful, making this an excellent source of Mining experience.
Once mined, players must construct the patch 11 times using the planks, with each action giving Construction experience, also scaling to the player's level. No planks are required as Zahra made planks using the Acadia logs.