Colombo Fort and Pettah — what is actually worth seeing and is it safe to walk around?

I have lived in Colombo my whole life and walk these areas regularly. Here is the complete honest guide.

The Fort area: the Fort is the colonial administrative and commercial heart of Colombo, not a historic fortified zone — the physical fort walls were demolished long ago. What remains is a concentrated district of British colonial architecture worth seeing: the Old Parliament building (now Presidential Secretariat, on Galle Face Drive), the General Post Office, the Grand Oriental Hotel, the clock tower, and the Bank of Ceylon area. The architecture along Janadhipathi Mawatha has a formal colonial character quite different from the rest of the city. Galle Face Green — the 500m seaside promenade immediately south of Fort — is the best place in Colombo to watch sunset over the Indian Ocean alongside everyday local life.

Pettah: the historic market district immediately north of Fort across the railway line. It is safe, it is busy, it is authentic, and it is fascinating. Each street specialises in a trade — electronics on one street, fabrics on the next, spices, hardware, dried goods. The specific highlights:
Jami Ul-Alfar Mosque (the Red Mosque on 2nd Cross Street): the candy-striped red and white mosque built in 1909 is one of the most visually striking buildings in Colombo and a functioning place of worship. Remove footwear before entering, respect prayer times.
Manning Market (off Main Street): the wholesale produce market. Come before 10am for the full activity — fruit, vegetables, and the commerce of a working city market.
Main Street and Front Street bazaar: the open-air trading that defines Pettah and has for centuries. Cheap, chaotic, and very photogenic.

Is Pettah safe? Completely. Colombo is a safe city for tourists. Standard urban awareness applies — keep your phone in a pocket in the crowd, do not display expensive camera equipment unnecessarily — but there is no specific threat to tourists in Pettah. Locals will help you if you look lost.

Best time for Pettah: morning, 8am–noon. The market is at peak activity, the light is good for photography, and it is slightly less punishingly hot than the afternoon. By 2pm the midday heat in the open streets is significant.

Galle Face vs Fort/Pettah: different purposes. Fort and Pettah are for history, architecture, and market culture — a morning activity. Galle Face is for atmosphere, sea breeze, and watching city life — an evening activity. Do both in the same day: Fort/Pettah in the morning, Galle Face at 5:30pm for sunset.