Željava Aerodrome, a vast underground military airbase on the border of Croatia and Bosnia and Herzegovina, was one of the largest and most advanced in Europe during the Cold War. Built by Yugoslavia in the 1960s, it featured a network of reinforced tunnels carved into the Plješevica mountain, designed to withstand nuclear attacks.

The base could house MiG-21 fighter jets and had its own power, water, and ventilation systems, allowing operations to continue even under siege. Abandoned after heavy destruction during the Yugoslav Wars, the site remains largely intact but deteriorating, with its runways and tunnels now left to the elements.

The entrance to the Great #Pyramid of #Giza, also known as the Pyramid of Khufu or Cheops, is one of the most iconic features of this ancient structure...

The Great Pyramid of Giza stands as a testament to the architectural brilliance and engineering skills of ancient Egypt. Constructed during the reign of Pharaoh Khufu around 2560 BC, this magnificent structure is the largest of the three pyramids on the Giza Plateau and one of the Seven Wonders of the Ancient World. Rising to an original height of nearly 147m, its construction involved the labor of thousands of workers over a span of about 20 years. Composed of an estimated 2.3 million blocks of limestone and granite, its precise alignment and complex internal passageways have intrigued historians and archaeologists for centuries. The Great Pyramid continues to captivate the imagination of people around the world, symbolizing the rich history and enduring legacy of ancient Egyptian civilization.

The original entrance was located on the northern face of the pyramid, approximately 17m above the base. This entrance was designed as a narrow passage leading into the internal corridors and chambers of the pyramid. It is believed to have been carefully sealed after the pyramid's completion to protect the burial chamber and its treasures.

In modern times, visitors do not use the original entrance. Instead, they access the pyramid through what is known as the Robbers' Tunnel, an alternate passageway created around 9th Century AD, during an attempt to uncover its secrets. This tunnel bypasses much of the original design and provides entry to the Grand Gallery and the King's Chamber.

The original entrance and its placement were part of the precise architectural planning that has amazed historians and archaeologists for centuries. The Great Pyramid's design, including its intricate internal passages, remains a subject of wonder, symbolizing the incredible ingenuity of ancient Egyptian engineering.

Kokorin Castle, situated in the Czech Republic's Central Bohemian Region, a medieval fortress nestled atop a rocky outcrop overlooking the Kokorin Valley.

Constructed in 14th Century AD, under the reign of King John of Luxembourg, it served as a crucial defensive bastion throughout its history, witnessing conflicts like the Hussite Wars and the Thirty Years' War. Evolving over time with architectural modifications, the castle boasts well-preserved fortifications, including towers, living quarters, and a chapel, all set within a captivating landscape.