Norbis Travel in Thessaloniki is one option (Lonely Planet suggests there are others)

Telephone: 2310287721

The bus does not depart from a regular Thessaloniki bus station but from Makedonikis Aminis 7.

It goes only once per week on Mondays at 7:30 am.

The price is € 120.

The trip takes 36 hours from Thessaloniki.

(I will keep the bounty open since I still there are apparently other possibilities besides this and I would also like to include the info for Athens)

Norbis Travel in Thessaloniki is one option (Lonely Planet suggests there are others)

Telephone: 2310287721

The bus does not depart from a regular Thessaloniki bus station but from Makedonikis Aminis 7.

It goes only once per week on Mondays at 7:30 am.

The price is € 120.

The trip takes 36 hours from Thessaloniki.

(I will keep the bounty open since I still think there are apparently other possibilities besides this and I would also like to include the info for Athens)

Norbis Travel in Thessaloniki is one option (Lonely Planet suggests there are others)

Telephone: 2310287721

The bus does not depart from a regular Thessaloniki bus station but from Makedonikis Aminis 7.

It goes only once per week on Mondays at 7:30 am.

The price is € 120.

The trip takes 36 hours from Thessaloniki.

(I will keep the bounty open since I still there are apparently other possibilities besides this and I would also like to include the info for Athens)

Norbis Travel in Thessaloniki is one option (Lonely Planet suggests there are others)

Telephone: 2310287721

The bus does not depart from a regular Thessaloniki bus station but from Makedonikis Aminis 7.

It goes only once per week on Mondays at 7:30 am.

The price is € 120.

The trip takes 36 hours from Thessaloniki.

(I will keep the bounty open since I still there are apparently other possibilities besides this and I would also like to include the info for Athens)