Sirena Beach

Sirena Beach is a part of Isle Delfino, a beach which is the target of electric Goop in Super Mario Sunshine, and the home of Hotel Delfino, a unique four-star hotel. It appears to be locked in a state of perpetual sunset. It includes a snack bar, 2 pools (one in the form of a sauna), and a Casino. The hotel is, in quite a few episodes of the level, being attacked by Boos. The hotel owner allows Mario to enter to hotel at no cost in return for exterminating the Boos and defeating Phantamanta.

Sirena Beach is also the level in which the Phantamanta boss is fought. Mario also fights King Boo here in the Casino. Peach, Toadsworth, and the Toads were probably meant to stay here, but because of the crisis, their stay was cancelled.

Once Mario enters the Casino he can't go back into the main lobby. And he also can't get back outside once he goes in the hotel. The pipe that leads to Sirena Beach is covered by a pineapple that only Yoshi can eat. The pipe is red.

Episodes
Episode 1: The Manta Storm
 * Hotel Delfino has been completely covered by electric goop and has sunk into the earth. Mario needs to fully defeat the Phantamanta in order to receive the Shine Sprite. Once Phantamanta is defeated, Hotel Delfino is restored.

Episode 2: The Hotel Lobby's Secret
 * The hotel is back, but the lobby is filled with Boos. Mario needs to use the Pink Boos in order to reach the top of the totem pole which has a golden statue of a Boo. Mario will have to jump into it's mouth in order to go to a secret level with the Shine Sprite.

Episode 3: Mysterious Hotel Delfino
 * The hotel is operating. Mario needs to use Yoshi in order to access the pool room from the attic to get to the Shine Sprite and to access the yoshi egg, Mario must find a pinapple.

Episode 4: The Secret of Casino Delfino
 * The hotel is now open. Mario needs to find a way to get triple 7's on the big slots and solve the Shine Sprite puzzle. After solving the puzzle, the player wlll end up in a secret level.

Episode 5: King Boo Down Below
 * The casino has closed down. Mario has to defeat King Boo by the use of Chili Peppers, water, and fruit.

Episode 6: Scrubbing Sirena Beach
 * The goop has returned, and Mario needs to clean most of the beach in under three minutes.

Episode 7: Shadow Mario Checks In
 * Another Shadow Mario appearance. This time, some of the Boos will look like copies of Shadow Mario.

Episode 8: Red Coins in the Hotel
 * Mario needs to track down eight Red Coins in various places in the hotel. Mario has five minutes to do this task

Official Profiles and Statistics
''The gentle lapping of the sea accompanies spectacular sunsets and romantic dinners beneath starry skies. The 4-star Hotel Delfino has it all.''

Trivia

 * The music of Sirena Beach is mostly inspired by Hawaiian music (albeit adjusted to be slightly unsettling). While an upright bass provides a steady bassline, a steel guitar slides repetitively.
 * Sirena is "Mermaid" in Italian so the translation would be "Mermaid Beach". Synthesizer and maracas play constantly in the background, while electronic organ and acoustic guitar also contribute to the disturbing melody.
 * It may also be noted that "Sirena" is similar to "Serene." The Sirena Beach is indeed a serene place.
 * In Super Smash Bros. Brawl, the pipe to the beach is absent in the Delfino Plaza course.
 * The goop in Episode 6 is arranged into a smiling Boo shape.
 * The music in the hotel's casino was used in Super Mario 64 DS and New Super Mario Bros. in Luigi's minigames, but did not have the saxophones or whistling.