The longest hiking trail is Snowman Trek in Bhutan, stretching from Laya to the high Bhutanese Himalayas and being built by the country's yak herders. It is one of the world's most difficult trekking trails due to the harsh weather, duration, and altitude, and only a few people have completed it. Bhutan Inbound Tour can help you to enjoy this type of trekking. For more info visit here: