We are planning to do a 5-6 week train trip from Thailand to Singapore. I feel like we have the larger cities staked out (Cheng Mai, Bangkok, Georgetown, Kuala Lumpur, Singapore) and now want to pick some smaller towns along the way. Any suggestions are greatly appreciated.
Take a look at the Cameron Highlands district to the north of KL. Can google it to see what it's all about, but basically it's where many of the old tea plantations are located, along with orchards, nurseries and other agricultural attractions.
The Highlands are at at elevation of 5,000 ft., making them a cool and pleasant respite from the rest of the country. It's going to be hot and humid during the time of your proposed visit - the Highlands might make for a nice change for a few days. Getting there may require a private car service - don't believe the train goes up there.
Another suggestion is the port of Malacca which as I recall is serviced by rail from KL. The place has a fascinating history dating back to colonial times (Portugese) and is probably one of the top tourist destinations in Malaysia.
Ipoh (Perak) is a good town for 2-4 days with spectacular Buddhist Cave Temples. We also enjoyed Taiping, a more quiet city with a large beautiful park. The train no longer goes all the way to Malacca although there are reasonable taxis from the closest rail station, about an hour drive. Malacca is definitely worth a visit.
I like Krabi - in far south Thailand - its a nice town anyway with nearby beaches - but its also a gateway to the southern Thai islands = you can island hope from Koh Lantra to Koh Lipe all the way to Malaysia ie Langkawi if you wish - you could pick the train back up at Georgetown
Thanks for the great recommendations. Hopefully, we can go within the next few years.