On 30 December 1973, a diverted and extended line was opened under the park to Mexikói út station, and a new underground through station was opened at Széchenyi fürdő. At the same time, Állatkert station was abandoned.
On 30 December 1973, an additional route was created beneath the park to Mexikói út station, and a new passage was opened at Széchenyi fürdő. Concurrently, Állatkert station ceased operations.