The embedded tower is actually right next to the safari zone. you will need surf and rock climb for this. first you need to get down to ground level via the ladders. then go outside. use surf and keep on going west until you cant go any further. then go up the rocky wall using rock climb. then go inside the cave.
p.s. in soul silver you need the red orb from mr Pokemon to catch groudon. you will not be able to catch kyogre. in heart gold you get the blue orb from mr Pokemon. if you manage to get kyogre and groudon into one of those two games go to prof. oak in pallet town and he will give you the jade orb. and go to the embedded tower and you will be able to catch rayquaza
head to the embeded tower
it is the object to summon rayquaza. take it to the embeded tower in Pokemon heart gold or soul silver
There is no Brass Tower.
Lugia-bell tower, Ho-oh-the whirl islands,Raiku/entei- roam around, suicune-past bills grandfather house at cuerlean, Groudon-Embeded tower with red orb, Rayquaza-after obtaining kyogre he is at emebeded tower. Also lots of event pokemon.
At Embededd Tower
You have to get into the tower and beat team rocket.
You get kyogre in heart gold only after beating pkmn trainer red then go to mr pkmn an get blue orb gd to embeded tower and save before capture you get grouddon the same way in soul silver but you get red orb
violet city
You don't. Kyorge was a Pokemon exclusive to HeartGold. You are required to get it in a trade. once you have Groudon and Kyorger(Both from the Embeded tower) you go to prof. Oak and he'll give you the green orb.then you go back and you'll face Rayquaza
Just save the radio tower....you will get it as a reward.
Sprout Tower.
goldenrod city.