The Romans also made huge advancement in military technology. Josephus the Jewish historian speaks about a few of the powerful weapons of the Romans.
The Romans also were able to use the plastic properties of the concrete to build fancier buildings.
The Romans also had the ability to flood amphitheaters to put on spectacle and even stage naval battles. This was quite amazing. There is a great article on this by C. Coleman in the Journal of Roman Studies.
Finally, the Romans also build great bridges.
For more information on Roman architecture, read the ancient Roman author, Vitruvius.