The Knossos site is just outside Heraklion, at the other end of the island, but we sat on the coach all day to spend two hours looking at this site, because it is so famous and interesting. Internet sites can best give you a full history, but basically the artificial hill containing the ruins was bought by Englishman Arthur Evans in the latter years of the 19th century, and he both financed excavations, and what is controversial, rebuilt some of the buildings in concrete to make them look as they once were. What is remarkable about the findings was how advanced the Minoans were, how they abstracted water uphill and had very advanced plumbing including flush toilets.
Below is a plan, giving an idea of the size of the palace. A scale was not given, but the site runs over a whole hillside...

Below: the double-headed axe, symbol of the Minoan king, still etched in the stone:
These pits were for waste from animal sacrifices...
Arthur Evans himself:
A retouched fresco from the throne room, the original having been removed and taken to the Archaeological Museum at Heraklion:

More of the same room, again retouched...

And here is the original throne, fortunately left in situ...

The sacred double horns, the symbol of the Minoan religion:
A re-created fresco from one of the rooms, the original having been transferred to the Museum in Heraklion city centre...

A lot of the site was given to storage, and these are original jars which stored wine and grain. Note in the background the size of the opposite valley side, which gives an idea of the size of this site...
Below, some of the less stately rooms, but giving an idea of the precise engineering used to design and build the palace...
The dolphin fresco above is also re-created, but the doorways are original. The dolphin featured a lot in Minoan art

Original, but re-painted, part of the palace...
This is the Queen's promenade, a large courtyard where she would take the air (which was very hot in that valley).