What is the fine-grained topic of the following text: It's a good thing that the Mongol Rally 2016, a 10,000km car race across Europe, is going to finish somewhere near Russia next summer because I've got to make it to the start of the Mongol Derby 2016, a 1,000km horse race throughout Mongolia. Only return the topic.
Participation in the Mongol Rally and Mongol Derby 2016