The distance between the Louvre museum and the Eiffel tower is 4 km. ---it's 3km as the crow flies...taking surface streets would add a little, but not much...3 km is about 1.9 miles, by the way.
The Eiffel tower is 324m high which would give a theoretical distance to the horizon ( if the surrounding land was perfectly flat) of 64.9km. However, the highest observation platform is at 276.1m...