Hope that some have found these posts informative. I am listing them below:
The standard answer to this one is Kanyakumari (also called Cape Comorin), which is indeed the southernmost point on the Indian mainland. Unlike the other extreme points, this is well populated and linked to other parts of the country. It is officially at 8.078 N, 77.541 E. Here is the main tourist area:
The southernmost point on the mainland would probably be the place marked “Hidden twin beach”.
The railway station seen on this map has trains to all corners of India, including Katra in Kashmir and Dibrugarh in Assam.
Kanyakumari was earlier in Travancore state, then Travancore-Cochin state and was finally transferred to Madras state (now Tamil Nadu) when linguistic states were formed.
But the true southernmost point of India lies in the Andaman and Nicobar islands (not the islands of Lakshwadeep as their southernmost point is around the same latitude as Thiruvananthapuram). To be precise, the southernmost point is a settlement called Indira Point on the southern tip of Great Nicobar island.
This article mentions that there are 4 households in this settlement with a total population of 27 (all males). It also mentions how many are literate and how many are from reserved categories. Presumably most (if not all) of them are connected with the lighthouse.
Here is a video of the area shortly after the tsunami of 2004: https://www.youtube.com/watch?v=XRA4sCNTN4E
Note how the lighthouse has sunk into the water. It is functioning again now.
There appears to be a helipad nearby. Also note the numerous small buildings near the lighthouse.
While tourism is being encouraged in some parts of the Andamans, even Indian citizens cannot visit Nicobar district without permission from the union territory’s government. There are ships and helicopter services to nearby Campbell Bay, which has India’s southernmost airport and naval base.
It is not often appreciated that these islands, particularly in the Nicobar group, are considerably closer to other countries than to India. This map should give an idea:
The straight-line distances from Indira Point to various places in India:
Port Blair-554 Km
And to some places in other countries:
Banda Aceh, Indonesia-215 Km
Phuket, Thailand-515 Km
Think about it. Indira Point is closer to Indonesia and Thailand than to Port Blair. And Yangon and Colombo are closer to it than any mainland Indian city.
The Andaman and Nicobar islands were occupied by Japanese forces during WW2, and were nominally governed by the Indian National Army.
Regarding the research stations in Antarctica starting with Dakshin Gangotri, it appears that India does not have any territorial claims over Antarctica while some other countries do.
Arakkonam (formerly Arkonam) is well known to railway followers because it is an important junction as well as electric loco shed, but has recently come into prominence because the inundation of Chennai airport caused some commercial flights to be operated from there. To be precise, this is the NAS (Naval Air Station) at Arakkonam which the Navy calls INS Rajali.
Most basic information can be seen here:
Although it started off as an IAF base in the 1940s, it was abandoned soon after WW2 and was reactivated for the long-range reconnaissance aircraft of the Navy during the late 1980s. The TU-142s and now the Poseidon P-8s have made good use of the 4.1 km runway which has been claimed to be the longest military runway in Asia.
Here you can see the locations of Chennai international airport (MAA), IAF Tambaram and INS Rajali marked with the small gold stars.
One can see that INS Rajali is about 50 km west of MAA, while IAF Tambaram is only 10 km away. At least there is no chance of a confused airline pilot landing his 747 at INS Rajali by mistake, though this has happened once at Tambaram in recent years.
Here is a closer view of INS Rajali:
Though it is not very clearly shown, the railway line from Chengalpattu runs along the highway right by the boundary wall of the base. The Railways have been planning to electrify this section for a long time but the Navy have objected to the presence of the traction equipment being an obstacle to the flight path. Thus an alternative line is being built further from the airfield, but this seems to have dragged on for several years. This new line is not shown in the map. Meanwhile the diesel-hauled trains continue to run past the base.
This is not the first time that military airfields have been used a a backup. Sulur for Coimbatore and Avantipur for Srinagar are other examples. The inaugural flight of Jet Airways to Coimbatore did land at Sulur by mistake. Apart from the Saudia 747 which wrongly landed at Tambaram, there have been several incidents including a mid-air collision and another which totalled a DC-8 which were caused by the proximity of BOM to Juhu. More about these later.
With all these movements of heavy aircraft, it is fortunate that this airfield has not seen a major aviation accident yet. However, India’s experimental AWACS on an Avro frame did crash a few km away in 1999, apparently putting an end to DRDO’s efforts in that direction.