'Eth Alth'eban (Arabic for Snake's Nest) was a sacred city where the League of Assassins was born and served as their secret headquarters hidden from the prying eyes. This wondrous paradise served as the basis for what Ra's Al Ghul desired for the rest of the world. At some point, the Untitled became a threat to the League who placed magical wards to protect their home from their god-like power. However, they sensed the dangers posed by those beings and thus Bronze Tiger sought out Jason Todd as it was determined that he was the only person capable of defeating this threat. As a result, they abducted him and brought him to the hidden city where they asked him to lead them against the Untitled.
"Deep in the Arabian Peninsula lies the hidden city of ‘ETH ALTH’EBAN, the ancient stronghold city of The League of Assassins. It’s hidden in a labyrinthine series of canyons in the middle of the desert. It’s entrance should be reminiscent of the entrance to the Al Khazne temple near Petra (which you might find familiar from Indiana Jones and the Last Crusade)… The primary difference is that there should be accents of copper throughout, including gigantic copper doors. The design should also have a snake theme, to it… with decorative snakelike flourishes. It should look ancient, aside from the copper which is polished and shining. The whole entrance is carved into the wall… It’s been standing for generations, hidden away from the world.
Inside these walls is another story altogether… After proceeding through the doors and opening a high tech series of barricades, you find yourself somewhere spectacular… It’s an underground technological eco-paradise, with the architectural styles of a pre-Islam Arabia. It’s an unspeakably massive setting, with a huge artificial sun in the roofs of the cavern. It’s a full city under the ground, filled with the most dangerous people who have ever lived.
This is Ra’s al Ghul’s utopian paradise. This is what he has wanted to bring to the world for all these years… A place of magic, incredibly advanced technology, and nature, all together in a small bubble of paradise.
Imagine it co-existing with luscious, tropical vegetation and wildlife… Hanging gardens, tropical birds, and crystal clear waterfalls built into the seams of the place… It’s like a beautiful city built into a nature preserve.
On top of this, there should be evidence of incredibly advanced technology, mixed in with the ancient, colorful architecture and wildlife. There should be smart-glass displays in the windows, and old style markets selling the most dangerous high tech weapons known to man (right across the aisle from a fruit-stand). The population of the city should not be predominantly Arabic, but more pan-global. Every person in there is a killer, or someone involved with the death industry. Showing the market, we should see 5-Star Generals in full regalia walking side by side with ninjas, next to people in suits of fully robotic killer body-armor. They’re all enjoying the freedom of the place.
Everyone should have a hint of danger to them, but there shouldn’t be a unifying code of dress or anything like it. It needs to be fluid and strange and contradictory in its elements to keep every moment visually dynamic.
Also: In terms of the foot soldiers of the League of Assassins, I want to keep the Ninja Man-Bats… So we should always see a few of them flying around the place, particularly in the wide shots of the spires and towers of the place. We can see them flying around, or resting on the rooftops and minarets. It’s an added touch of color that I think really elevates the entire place.
In the center of the city there should be a giant statue of Ra’s al Ghul holding the artificial sun at the roof of the cavern, towering over the buildings and spires. At the feet of the statue, there should be a large, ornamental fountain that has been sealed up with a polished copper lid with ancient marking and runes in Arabic, Chinese, Cyrillic and Celtic characters.
The largest building should be like a palace, directly behind the statue of Ra’s Al Ghul and the fountain beneath it. This is where Bronze Tiger and the ruling council of the League of Assassins has been running the show since Talia left to wage her battle with Batman in Gotham City."