It would depend on how large your Greek Tortoise is. If he is still a small Tortoise you can purchase a large cement mixing container at Home Depot or your nearest Hardware store.I also purchased a 5x5 purchase of indoor outdoor carpeting. I cut a couple of pieces that fit the inside of this container, to use as a base area for your tortoise to use as the flooring and also purchased a small heating pad that doesn't turn off automatically for my small tortoises to sleep on when they need warmth. You will also need a heat lamp and proper UVB lighting for your tortoise when they are inside, but pls try to take him outside when its sunny and warm enough to get him the proper sunlight that he will need. Contact a Turtle/Tortoise Society in your area for additional information and help as well as there are many good books as well as web sites that will tell you how to properly care for you wonderful Tortoise. Good Luck!