The Taj Mahal is truly a wonder of the world and definitely worth a special trip if you are visiting India especially with completing the golden triangle journey in mind. Some folks stay in Agra or come from Jaipur. I took a train early from Delhi and since it was the express, it made it possible to make it a day trip there and back. The train is specifically the Gaitman Express (#12050) which leaves Delhi (Hazrat Nizamuddin station) at 0810 and takes about 2 hours to reach Agra Cantt station. The return to Delhi is train #12049 that leaves at 5:40pm. I recommend buying the tickets in advance either in GC (General class) or EC (Executive Class) for a few hundred more rupee. If doing the latter it will be about 1200 rupee each way. The EC came with a sizeable breakfast of fruit, bread, crackers, and coffee and the leg room is more noticable than GC which is what I took back to Delhi. Note before going through all of this that the Taj Mahal is NOT open on Friday's! I recommend buying the train tickets in advance. You must register with the Indian Railway IRCTC, which was a slight learning curve. This gives you a IRCTC userid needed to buy any train tickets.

After arriving in Agra and leaving the station I recommend using Uber to arrange for a very cheap ride to the Taj Mahal, which takes 15min total. Upon leaving your Uber note the big blue signage describing the entrance location. You will need your ticket physical or electronic to give to the concierge to scan you in. After that you will need to go through security very similar to an airport with conveyor belt and body wand. Note that you cannot bring any food inside, no exceptions. Liquids are ok. Once finished with security, you are now free to wander to the Taj. You will meander a bit until you reach an open square and the main gate entrance to the Taj in sight. It is likely you will be pestered by several individuals offering to be your guide. I chose to disregard and complete the experience solo. Once through the main gate, you will clearly see why it is one of the wonders of the world. In the distance, it's marvel, majesty, and size are very apparent.

Take some time to strolll through the tree groves on either side of the center walkway and view the garden then make your way to the central terrace for a good photo op while the Taj Mahal is still at a distance. Once entering the Taj Mahal square you will see a ramp way to your right which is the general entrance. You will approach the Taj Mahal from that side, take a short walk around the building to the other side where you will see a ticket counter for the Mausoleum entrance at a cost of 200 rupees. With ticket in hand, take shoe covers as they are needed to enter the Mausoleum. After a ticket check, you will make your way to the Mausoleum via some steps and hopefully a short queue. Once inside know you are not allowed to take pictures, so soak in the wonder in your mind. The Mausoleum experience takes about 5 min to make it through, so very short. Upon conclusion, you are deposited outside the Taj Mahal and free to wander until you are satisfied. If I recommend anything, it is to buy your train tickets and Taj Mahal tickets in advance. Makes the uncertainty such as a queue or line more manageable without wandering where to go or risk missing your train.