where is halfway between newcastle and london
Gulf coast states, Florida, Texas, etc. There are ranches that have them in Texas.
East coast usa
Valdosta, GA
Cape Canaveral, Florida... on the east coast about halfway up the state.
Daytona beach
around the coast of Africa
If you want to find the shortest distance from the east coast to the west coast then Florida is considered an east coast state. It's only 1763 miles from the coast at Pensacola, Florida to San Diego.
The distance is about 4,193 air miles from coast to coast.
The halfway points are the points which mark the half distance covered by the flight. These lie in the mid of both the above mentioned places. These points change for different locations. Halfway points for the above mentioned places are - Sri Lanka.
It would be close to Greenland, just off its west coast.
If you swing south, your halfway point along the coast would be around Bournemouth. If you swing north, your halfway point along the coast would be Bristol, which is less scenic but it's a direct shot on the M4 and M5.