The Grand Trunk Route is my favorite of all the historic train route as this route goes down the very core of India from the Himalayas in the North to the tropical Southern most tip , which is one of rare capes with a trijunction of seas (and Ocean).

Prestigious trains ply this route,  including the Grand Trunk Express. This train started service in 1929 and is still very popular with travelers. At inception the train ran from Peshawar in the current day Pakistan to Mangalore 

Today, the grand trunk route will give you an all India experience comparable to none. With several super-fast express on the route, this busy trunk route offers several departures that makes it easy to discover several heritage, cultural and natural wonders of India. The Tamil Nadu Express, HimSagar express, Kerala express and the Rajdhanis to name are a few of notable trains on this section.

Sample Itinerary

Start in New Delhi. Get lost in the havelis of Old Delhi, shop in Chandni Chowk and get some tasty treats at the paranthe wali gali. Take a conducted city tour to check off guidebook top attractions.

Take one of the fastest Indian trains, the Bhopal Shatabdi to Gwalior to see a Rajput Fort. Enjoy some classic Madhya Pradesh cuisine.

Next Stop, Jhansi and Orchha. Dig deep into your guidebook and you will have a line or two on Orchha. Search the internet and you will come across a few references to this magical place on the Betwa river. No too touristy, but touristy. An authentic destination unlike those on the golden circuits with endless parade of tourist coaches. 

There are plenty of trains from Jhansi to Bhopal, better yet Vidhisha if your express train stops here to marvel at the Buddhist stupa in Sanchi. 

Nagpur or Wardha is your next stop to Sevagram. Learn all about Mahathma Gandhi in his ashram and discover peace.

Vijayawada, Nellore or Ongole would be a good stop for Andhara Pradesh, a state known for spicy food. You will also notice that the staple switched from wheat flatbreads to rice. 

Marvel Chennai at the end of the line. Marina beaches and the Dravidian granite temples. Rest up in five star luxury before exploring South India and Kerala or hop on in one of the many low cost airlines to Sri Lanka, Malaysia or Thailand to continue going around the world.

Kalka mail is the oldest running Indian train. It connects the old British India capital Calcutta to Kalka the foothills of Shimla, the summer capital of the British Raj. The service was first introduced in 1866. It used to carry British civil servants in charge of 'governance' in India between their summer and winter administrative work places. Must have been a spectacle then when several Indian servants would transport everything from linens, china and other worldly possessions for a few British masters. These days , the train renamed Netaji Express carries students, professionals and tourists from around the world.  Must be an experience if you were a Brit and your great-grandparents used this line and you are riding it now.

Connects to Kalka-Shimla Railway.

The present day Frontier Mail is now the Golden Temple Express that plies the portion of the Historic Frontier mail between the western port city of Bombay and the North West frontier city of Peshawar on British India's frontier with Afghanistan. Frontier mail's first service was in 1928 and it connects Mumbai and Delhi with Amritsar in Punjab.