We have a triumphal arch, similar items to which are still seen in today in monuments such as Marble Arch and the Arc de Triomphe. This dimensions of this one are based on the Arch of Constantine in Rome.
There’s also a Roman bridge with a smaller arch and two lighthouses/beacons, based on the remains of ones in the UK. Finally, we have a pair of obelisks and a Funerary Tower (a tomb, essentially). All good for your Roman city, or in more modern layouts since the arches and obelisks are still in evidence in many European towns and cities today.
SSS-8100 – Roman Triumphal Arch – £1.50
SSS-8101 – Roman Bridge with Arch – £1.00
SSS-8102 – Lighthouses – £1.50
SSS-8103 – Roman Obelisks and Funerary Tower – £1.50