Has there been a modern day Troy 'discovered' in the last 50 years, or an unknown city or evidence of a previously known civilization, or evidence that has caused a revision of previous theory?
I'll use an example most familiar with me. Archaeologists did not recognize much surface architecture in West Mexico until fairly recently. In the late 60s/early 70s Phil Weigand and his wife were the first to systematically record the temple-groupings known as guachimontones which date to the Late Formative to Classic period (300 BC to 500 AD). They consist of centric rings with a stepped central altar, a ringed patio space, and a ringed banquette in which sit atop several quadrangular platforms. They are quite prolific around Tequila volcano in Jalisco.
There are also large platform structures from the Epiclassic (550 - 900 AD). These monumental platforms consist of three platforms on top of the large base platform. There is one platform at the back and two flanking it. Sometimes there is a small pyramid or platform in the "court" space of the platform. The most famous of these is probably the Palacio de Ocomo or the platform at El Grillo. El Grillo was surveyed and excavated in the 70s by Galvan, the Palacio de Ocomo is being excavated today.