is there any mistake?

[happys82]

The view is wonderful from the roof. We play football and other activities in the specially built field. Our pitch is surrounded with the net and it’s also worth seeing of islands and sea.

[sarat_106]

The view is wonderful from the roof. We play football and other activities/sports in the specially built field. Our pitch is surrounded with the net and it’s also worth seeing the (of) islands and sea.

I think, you do not need 'of' there. To me, sports sound better than activities.

[Jaskin]

hi,
Please note I'm not a teacher nor a native speaker,

Do you mean that the islands and see can be seen from the roof ?
If so then:

[...] pitch is surrounded with the net and it overlooks the islands and sea.

Cheers,