The oldest intact building in my city is from 1320 - so 700 years old. Baguely Hall, which is an old landowners hall.

The city itself - Manchester - dates back to the roman era and we have the remnants of an old castrum/fort in the city centre dating back to 79 AD - so 1945 years old. Surprisingly there were more complete ruins at the site but much of it was levelled during the industrial revolution.

Here in Curitiba it’s this church:

It’s constantly maintained and renovated, but the building is 287 years old, built in 1737. (For reference the city itself is 331yo.)

It’s kind of funny that people here don’t typically remember the name of that church, Igreja da Ordem (Church of the Order; the “order” in question are the Franciscans). Instead they remember the name of the square that the church faces, named after the church - o Largo da Ordem (lit. “Order Plaza”, but more like “the plaza of the church of the Order”).

When I lived in Germany for a couple years, I was surprised to learn that the large church in the center on my village was about 1,000 years old. This one building has been standing longer than America has been a country. Over 4x as long, too! European culture amazes me because there’s such a lengthy history, and so many things are much older than I’d imagine. American history is so short in comparison, and we’re more likely to tear down and build new and cheap than create a solid structure that will last for hundreds of years.

The castle down the road from me is pretty old. It’s from 79CE:

The Roman fort in Castlefield, Manchester, England, was founded around 79 AD. The fort was originally named Mamucium, but is also known as Mancunium.

In southern Spain you can’t dig without hitting some stone age stuff. My town was a known stop for travellers before the Romans took over because of fresh water wells. Eventually a roman road was built about two millenia ago, and still ride on it with my bike for some routes.

No old buildings remain, this was a roadside village and stuff was made cheap and not meant to last, but there is a funeral arrangement from 600 BC that was unearthed and sent to the national museum. More info

I’m sure there are older ones, but this one looks like someone left a few weeks ago even though it’s from the 1890’s. You can walk into it after a medium hike. There’s still soot in the fireplace.

https://californiathroughmylens.com/eagle-cliff-mine/

The really old stuff from the native Americans might be around but I’m not familiar with it.

Ye Olde Trip To Jerusalem, a pub which claims to be from 1189.

https://en.wikipedia.org/wiki/Ye_Olde_Trip_to_Jerusalem?wprov=sfti1#

Over 700 years. A tower originally built in 1310. The island it’s on is an exclave that is technically part of Hamburg.

Here, there is a 450 year old house that is now owned by a group of citizens who use it to arrange local events.

A church built in the 9th century, still in use today. Underground: Walls from the Roman empire, 2000 years or older. Dig deeper and you’ll find remnants of the stone age. Germany.

My guess is the cathedral that was started ca 1070. Other than that the oldest wooden buildings are from the 1700s.

The oldest church was built around 1200, on the remains of an older church from the 7th century and you can go below ground to view those. We also have some Roman ruins from a castellum build around the year 47 you can also go and view.

Edit: The castellum is gone, but there are just some walls and stones.

It’s hard to say for the village I live in. There really are not many officials records but apparently one of the roof tiles had 16xx marked on it. Which makes this totally unassuming house somewhere around 400 years old.

1904, maybe? It’s the only one I know the age of. Maybe the court house is technically older, probably is, but it’s been overhauled a lot.

This lighthouse is the oldest building in my city (Hamburg, Germany). It was completed 714 years ago. I actually had to look it up, I was kind of expecting the oldest building to be older than that.