AMTP stands for Association du Musée des Transport de Pithiviers.
This is an association for the preservation of historic rolling stocks of the former Pithiviers - Toury line.
Operating a short part of the historic line, AMTP is based at Pithiviers railway station (maps.app.goo.gl/sKKRXaniAhaiS..., which also houses the museum and the steam and diesel locomotive depot. Regular trains run to Bellebat station, the line's terminus.
More information on timetables : amtp-cfpithiviers.fr
More information on the association : fr.wikipedia.org/wiki/Mus%C3%...