Every Overlord needs a Seat of Power. It is from within the safety of this fortress that he is able to rule the world with an iron fist. It takes many years to actually finish construction of this building, and a lot of memory manipulation so that others do not know all the secret passages. We will leave all of that to a later lesson. Today we will cover the basics only.
The Seat of Power needs to be constructed in such a way as to instill awe at first site. The workmanship needs to be top rate. Splendor needs to adorn. Absolute power needs to be reflected at all times. Meaning, the building itself needs to convey the message that to attack this building, death will ensue. This building needs to be very well fortified. Every type of attack needs to be planned for. Against missiles, airplanes, and even cannons, there is very little to defend against. Do your best, and plan for the worst. Keep the attacking people away from the building. Put traps and machinery in place to take out the cannons, missiles, and even kamakaze airplanes. Keep them out. Make use of natural defenses whenever possible. Build on cliffs, surrounded by dangerous waters, or something similar.
If by chance the attackers make their way inside. The object has changed. Instead of keeping them out, you now want to keep them in. Wherever the attackers are, you need to be able to fire upon them, without being shot back. The hearts of the people can only last so long while their comrades are falling in droves, all around them.
Other than battle, your Seat of Power serves another purpose. At times, you will need to conduct business. To all invited guests, while they are within this structure, need to be constantly overwhelmed. They need a sensory overload of the majesty and raw power that you possess. Make them feel how insignificant they really are.
Inside the Seat of Power, is your Inner Sanctum. We will not discuss this now, but remember, this is your permanent living quarters. Since you are living in the Seat of Power, you will need escape routes, and backup supplies in case your plans fail, and the people come looking for you. Like the Boy Scouts, always be prepared. Plan for the absolute worst outcome. Plan even for your death. You have all that wealth and power. Let someone else take that with little or no effort? Of course not. Destroy everything upon your death. If they covet your position so greatly, make them work for it.
As you have no doubt surmised, this structure is of great importance. Start planning now. It will take you many years to conquer the world. Once you do, you can not delay. Work must commence immediately upon the greatest fortress the world will ever know.
Do not use elves in the construction in any way. They never forget, and will secretly build their own back doors and tunnels. Nasty, vile creatures!