Pokémon Diamond and Pearl/Valor Lakefront

Valor Lakefront connects Route 214 to Route 213 to the south and to Lake Valor to the west, which is blocked until you progress the story later on in the game. It also connects to Route 222, but you won't be able to go that way either for now.

Valor Lakefront

If you go to the top left corner of the grass area you will find a hidden Max Ether (DP). When you talk to the guys blocking the entrance they will say they are protecting the lake. Continue going down and will find a Parlyz Heal (DP) in the middle of the path. Go up the stairs and you will be at the Hotel Grand Lake.

Pokémon found

Diamond and Pearl
Pokémon		Level	Morn.	Day	Night
	Geodude	20	20%	20%	20%
	Graveler	21,22	15%	15%	5%
	Girafarig	21,22	30%	30%	30%
	Staravia	21,22	15%	15%	5%
	Bibarel	21,22	15%	15%	15%
	Kricketune	21,22	5%	5%	25%

Hotel Grand Lake

As soon as you turn left there is a lady that is looking for her room key that she lost. The Suite Key is hidden one step down from the left stairs above the reception area. While here, go up the left stairs and go into the room and speak to the clown to get TM92 Trick Room. Head back out and go give the key to the lady who will give you a Lava Cookie for finding her key.

If you try to go right before the Hotel Grand Lake, the guy will stop you and say that Sunnyshore City currently has a blackout so turn around and go left up the stairs and the first building you will see is the Seven Stars Restaurant.

Seven Stars Restaurant

In the restaurant, there are a bunch of trainers that will have double battles with you. The trainers randomly change every day.

Trainers

Diamond and Pearl
Trainer	Pokemon
Artist Ismael Reward: 2392 Double battle with Beauty Harley	Mr. Mime Lv. 23
Beauty Harley Reward: 2392 Double battle with Artist Ismael	Psyduck Lv. 23
Lass Blythe Reward: 2640 Double battle with Veteran Emanuel	Bidoof Lv. 21 Bidoof Lv. 21
Veteran Emanuel Reward: 2640 Double battle with Lass Blythe	Machop Lv. 23 Bronzor Lv. 23
Collector Eugene Reward: 2016 Double battle with Aroma Lady Alison	Clefairy Lv. 20 Clefairy Lv. 20 Clefairy Lv. 20
Aroma Lady Alison Reward: 2016 Double battle with Collector Eugene	Roselia Lv. 23
School Kid Esteban Reward: 2184 Double battle with Pokéfan Meredith	Wooper Lv. 23
Pokéfan Meredith Reward: 2184 Double battle with School Kid Esteban	Marill Lv. 21 Aipom Lv. 21
Scientist Emilio Reward: 2112 Double battle with PKMN Breeder Kaylee	Kadabra Lv. 23
PKMN Breeder Kaylee Reward: 2112 Double battle with Scientist Emilio	Stunky Lv. 21 Buizel Lv. 21
PI Kendrick Reward: 5176 Double battle with Beauty Gabriella	Goldeen Lv. 22 Goldeen Lv. 22
Beauty Gabriella Reward: 5176 Double battle with PI Kendrick	Finneon Lv. 23
Gentleman Leonardo Reward: 10800 Double battle with Socialite Rebecca	Starly Lv. 21 Hoothoot Lv. 21
Socialite Rebecca Reward: 1080 Double battle with Gentleman Leonardo	Lopunny Lv. 22 Glameow Lv. 20
Cameraman Darryl Reward: 1592 Double battle with Reporter Valerie	Luxio Lv. 21 Pikachu Lv. 21
Reporter Valerie Reward: 1592	Murkrow Lv. 23
Rich Boy Roman Reward: 8320 Double battle with Lady Kylie	Sudowoodo Lv. 23
Lady Kylie Reward: 8320 Double battle with Rich Boy Roman	Bonsly Lv. 21 Pichu Lv. 21

Once you finish all your battles here then head back and head further lefr to the last building for a surprise when you complete your Pokédex.

Game Creator

The man inside the furthest most building is a game creator who will give you a diploma when you complete your Pokédex.

Below this building is a pool and underneath the umbrella is a hidden Hyper Potion (DP). Once done here, head back through the reception area to be on your way to Route 213.