Category: Trekking Permit

Is it possible to buy a permit in advance on the Internet? We want to go to langtang and back to KTM via gosaikunda

How long is validity for permit to national parks for Annapurna, Langtang? Is it enough time to do some side trips, or just enough for standard trek route? For example Annapurna circuit + Mardi Himal + Khopra Ridge, etc?