The type, size and material of an outdoor fireplace depend largely on what you expect from your outdoor fireplace. If you are looking for a small, ambient flame producing low heat, but great looks then the most appropriate models for you would be clay chimeneas. They are the most popular models of outdoor fireplaces all over the world. But if small, intimate fires aren't your style and you want a larger fire, then you should consider cast iron models. They are a little more expensive but definitely worth the cost. They are incredibly durable and can withstand roaring fires and high temperatures. In addition, those models have the added feature of a safety grill and pitched chimneystack to contain hot ash and embers.