In red, you just follow the natural maze until you get to it. There are also signs giving you directions to it when you get close. In blue, I don't think it'll be much different than in red.
At the secret house of Safari Zone.
The secret Pokemon house is in the safari zone in fuchsia city. I used a very useful website to get to the secret house inside of the safari zone and it told me where I had to go. Use the link at the bottom and it'll tell you exactly where to go inside the safari zone to get to the secret Pokemon House. Once you are in the secret Pokemon house you will see a guy. talk to him and he'll give you the HM03 (Surf).
In red, you just follow the natural maze until you get to it. There are also signs giving you directions to it when you get close. In blue, I don't think it'll be much different than in red.
In fuschia city theres a safari zone in there theres a secret house in area 3 if you get there talk to the guy inside he will give you HM3 which will allow you to swim.
The Safari Zone?
at the end of the safari maze at the end of the safari maze
All I know is that the secret hut is in area 3 in Fuschia city in the Safari zone.
go to fuschia city
complete the safari zone challenge
its either the hm you get at the secret houde in the safari park or the one you get when you give the gold teeth (found in safari park near secret house) to the warden. teach it to a water Pokemon and press 'a' in front of water (you need a certain gym badge first though but you should have by the fuschia gym
get the gold teeth in the safari zone then give them to the warden he is in the house right to the Pokemon centre then you give him the gold teeth and he will give u strength!!!!
In the Safari Zone, at the Hidden House (buried far in).