jumping-off place
1. The point at which something begins. I know you're unhappy with their offer, so just consider it a jumping-off place and come up with a counteroffer.
2. A very distant location, possibly the farthest possible one. I know where the explorers on that expedition started, but what was their jumping-off place?
jumping-off place
1. A starting point for a journey or venture, as in This tiny village is the jumping-off place for our trek into the desert. This usage probably alludes to jumping into the water. [Early 1800s]
2. A very remote spot; also, the last place to be reached. For example, This was the jumping-off point for the first gold miners in Alaska. [Early 1800s]