The Lower Gate, as it's called by locals, is an area of historical and archeological value. A small museum of archeology was set-up in this place which you can explore and see the city's original fortifications.
Fee: €0.90
Wikipedia https://cs.wikipedia.org/wiki/Košické_městské_opevnění
Address 119/9 Hlavná, Košice 04001, Slovakia
Coordinates 48°43'6.952" N 21°15'32.817" E