How do I decipher this hotel address in Greece?

I am flying to Greece and need to stay in to a hotel called "Castello Hotel", in Patras (a city in Greece). I booked the room through hotels.com and thought everything was fine, until I noticed that there are two hotels with the same name.

This in itself is not a big deal, but these hotels also apparently have almost the same address, although they are in two faraway cities. I am very confused - maybe part of the reason is that I do not know Greek so I do not understand the addresses.

1. Here is the hotel I need to go to. It is in Patras, near the Patras university. Its address, accodring to Google Maps, is "Palea EO Korinthou Patron 21, Rio 265 00".

2. Here is the other hotel. It is in Athens, which is many kilometers away. Its address in Google Maps is "Palea Ethniki Odos Patron Athinon 21, Rio 265 00".

3. The address on my booking says "21, Old National Road Patras – Athens / 26500 Rio Patras". I am trying to figure out whether it corresponds to the correct hotel (1) or to the wrong hotel (2). The problem is, it is similar to both 1 and 2, but not identical to either of them!

   • In all three addresses, there are the same numbers - 21 and 26500;
   • In all three addresses, there is the name "Rio";
   • In address 3, there is both "Patras" and "Athens".

Can someone who knows Greek can help me solve the mystery, understand the different words in each address, and figure out whether I booked the correct hotel?