a hidden container with small prizes for people to find using GPS

The treasure in a geocache is usually cheap, with items such as key rings and small toy animals. “地理寻宝”的宝物通常都很便宜，比如钥匙圈和小动物玩具等。

to take part in the activity of using GPS to search for small hidden prizes

I asked if he would like to geocache with me. 我问他是否愿意跟我一起玩地理寻宝。