noun, verbal noun
You make departure from your home off into the great beyond. You will go to see the unseen, and hopefully make a great discovery.
This is a jukugo word, which usually means on'yomi readings from the kanji. You know the はつ part, which gets shortened to はっ. The 見 is unlike what you learned with 見, though.
In order to remember that this is けん, imagine you're going out to make a discovery of some strange new lands. With strange new lands, there comes strange new people. This one has a samurai named Ken けん on it. He's trying to discover new things too!
I found a caterpillar on a tree.
If you live in a foreign country, you'll make discoveries every day.
With this old map, you may be able to find some treasure.