Need 4-5 star a hotel for 8 walking distance to attractions in August, any suggestions?

I have been doing extensive research on Athens for my April trip. Are you adults or do you need family accommodations?

I am a fan of boutique hotels with large rooms and king beds, and that gave me fewer options.

Kokias7, one of the top hotels in Athens is Grande Bretagne, on Syntagma Square:
https://hotelbretagne.grandluxuryhot...BoCyB8QAvD_BwE

Kfusto, I don't know if you would consider this a boutique hotel, but if you are looking for large rooms with king-size beds a Superior Room at Hotel Cypria is worth considering. The Superior Rooms have sitting areas and huge bathrooms. It's my go-to hotel in Athens, and is only a few minutes walk from Syntagma Square. No views like the GB, but the breakfasts are excellent:
Superior rooms in athens | Athens Hotels | Athens Cypria Hotel, GA

The Grand Bretagne is wonderful and in a very good location. Next to it is King George Hotel, another luxury property.

We stayed at the Grand Bretagne, and walked to/from the Acropolis from there. It has a fabulous open-air rooftop breakfast space, with gorgeous full-on views of the Acropolis. The hotel property is very nice.

The next door King George looked very nice, also.

We booked the Bretagne hotel via CostcoTravel.com, which included ground transportation to/from airport and ferries, plus a concierge in Athens. We'd never traveled that way, but I had very little time to plan a week in Greece, so used CostcoTravel. We were very happy with the hotels and the service.

It was a stroke of luck to have a concierge when we arrived in Athens, who met us at the airport. She knew there was a ferry strike coming, which would have ruined our chances of getting from Santorini back to Athens' airport when we needed to. She asked our permission to spend a bit more $$$, and book a flight instead. As it turns out, this was a godsend, as many people were stranded on Santorini by the ferry strike.

We also stayed one night at a Westin property in Athens, The Astir Palace Resort, when we wanted a more relaxing location than Athens proper.
https://www.facebook.com/westinathens/

I am returning to Greece this May, after many years. I've done a fair amount of research on Athens hotels; after the Grand Bretagne, take a look at the Electra hotels--I think there are three in central Athens.