Unless you consider an entire manufactorum a shrine to the Omnissiah, the Cainopolis temple to Khorne is the largest single temple in the capital. This is despite both Slaanesh and even The Emperor having larger number of worshippers there. They both prefer having a number of smaller temples.
It is set within a large plaza, used as a parade ground for military ceremonies. The plaza is tiled in granite and is most notable for the wide rosebeds that provide a pleasant scent for people approaching the temple. The favoured roses are known as the Roses of Khorne, as their strong and thorny stems mean that if you want to pluck a flower, you will have to pay the price of blood, which the Khornites consider to be an act of religious significance. This appears to the same flower favoured by the Sororitas Order of the Bloody Rose as their symbol.
The principle architectural feature of the temple is its great dome. The dome is roofed in polished brass, itself covered by a protective lacquer provided by the Bringers of Renewed Greatness to prevent it from tarnishing. The granite facing is also decorated with brass inlays designed to look like rising flames, cunningly inlayed at different angles, so the flames appear to flicker as you move around the temple.
The surrounding support buildings also act as bastions, so that anyone who attacks the building can be caught in a cross fire. Underneath the building are shelters, so that the people of Cainopolis can shelter there and be protected by the faithful if the planet should come under attack again.
The main hall of the temple is under the dome. It lacks seating most of the time, as it is thought that the worship of Khorne is best done while standing and ready to fight if necessary. The hall itself is lit by eight great armorglass windows, one on each wall. These windows are each a double arched design, what is known locally as an axeblade design, and the stained glass is decorated with the images of mighty warriors. Quite a few of these warriors are notable loyalists, but still honoured for their courage and ferocity in defending humanity.
The inside of the dome is painted to resemble the night sky, with the eight struts supporting the structure are decorated to resemble eight sword blades meeting at the peak. This is considered to symbolise warriors swearing an oath of brotherhood.
One part of the temple was "salvaged" from a pre-liberation temple to the God Emperor and that is the organ. The polished brass pipes dominate one of the corners of the hall. This has resulted in jokes, by unkind Slaaneshi, about Khorne's mighty organ, which are not appreciated by the priests. The dome is considered to have excellent acoustics and the temple is known for its choir and orchestra. Khornite music is strong on the brass and percussion instruments, but other types of music are played as well during the concerts here.
Inside the temple can be found a number of relics, including the spiked club wielded by Mother Mathar as she threw herself against the Giorba's enforcers to avenge her murdered children, a letter written to his family by one of the soldiers who were teleported into the Pyroclast Retribution to save Slawkenberg from the mad inquisitor Karamazov, and the skull of the Orc Warboss Gargash, personally slain by the Liberator.
Due to the comparative grandeur of the building and Khorne's role as the "guardian of Oaths", the temple is a popular venue for weddings, as well as ceremonies such as newly graduated medicae swearing themselves to the "great battle against disease".
Cue several Ordo Mallus Inquisitors beating their heads against a wall, complaining that the Slawkenberg heretics are not doing it right.