Gates are important in architectural works, especially in famous places like temples. However, there are gates that seem to not be built to be opened. They are hidden in mysterious places, leading to unknown areas and hiding many interesting secrets.
In the world, there are 3 doors that are known as "unopenable". And in fact, later generations have not tried to discover the secrets inside them.
Taj Mahal

The Taj Mahal is a famous temple in India, voted one of the 7 wonders of the world.
Shah Jahan of the Mughal dynasty mobilized tens of thousands of people and over 10 years to build the Taj Mahal in memory of his beloved concubine. The mausoleum is 508 meters long and 350 meters wide.
Legend has it that the Taj Mahal contains the remains of Shah Jahan, his concubines, and endless treasures.
Today, the Taj Mahal is India's national treasure and no one is allowed to open its main gate.
Padmanabhaswamy Temple

The Padmanabhaswamy Temple in Kerala, southern India, has long been a holy place for people to worship.
Deep inside the temple, there are 6 sealed rooms. The first 5 secret rooms have been opened by later generations and a large number of treasures and ancient artifacts have been discovered. The preliminary estimate of the value of these treasures is more than 10 billion USD. However, the Indians do not use these treasures but still keep them in the temple.
Currently, the 6th room has not been opened due to methodological difficulties.
Mausoleum of Qin Shi Huang

Since the discovery of the Mausoleum of Qin Shi Huang, people have been curious about the cultural relics inside it, but until now the mausoleum has not been able to open.
The Mausoleum of Qin Shi Huang covers an area of at least 56 square kilometers, is a giant mausoleum complex with more than 400 tombs scattered around and took 39 years to complete.
Because of mistakes made during the excavation and research of the terracotta warriors and horses guarding the mausoleum of Qin Shi Huang, which caused them to fade, experts did not dare to open the mausoleum of Qin Shi Huang hastily.
In addition, the Mausoleum of Qin Shi Huang has a lot of mercury, which is extremely toxic, turning this place into a "door" that cannot be easily opened, and people are still full of infinite curiosity about the secrets inside.