What is the fine-grained topic of the following text: British Army Lieutenant John Wood reached the lapis mines for the East India Company in 1837, and wrote in his Journey to the Source of the River Oxus, “If you do not wish to die, avoid the Valley of Kokcha.” This is surely not one of the world’s better sites for a field trip! Only return the topic.
John Wood's exploration of the lapis mines in Kokcha Valley for the East India Company in 1837.