SHIRAHAMA KEY TERRACE HOTEL SEAMORE

SHIRAHAMA KEY TERRACE HOTEL SEAMORESHIRAHAMA KEY TERRACE HOTEL SEAMORE

Lodging

Nanki-Shirahama Onsen

Kansai·Wakayama

0739-43-1000 keyterrace.co.jp

Contact form

Day Use

Yes

13:00–20:00

¥1,000

Children (age 3 through elementary school) pay 500 yen, and bath towel rental is an extra 550 yen.

Bathing & Water

Natural onsen water

Uses natural hot spring water

Outdoor BathYes

Open-air outdoor bath

Indoor BathYes

Enclosed indoor bathing area

SaunaYes

Dry heat sauna room

Cold BathYes

Cold water plunge bath, typically used after sauna

Capabilities

Private BathYes

Private bath available for day-use visitors or hotel guests to reserve

The main onsen baths have no traditional family/private bath; the paid 'SAUNA HOUSE on' is a reservable exclusive-use facility with its own outdoor bath and cold plunge (explicitly not onsen water), booked in 2-hour blocks.

Mixed BathingNo

Shared bathing area for all genders

Policies & Services

TattooNo

Allows entry with visible tattoos

KidsYes

Welcomes children and families

The pool requires adult supervision for elementary-school-age or younger children.

DiningYes

Restaurant or dining open to visitors (not just hotel meal plans)

WashingYes

Shower, wash stations, soap and shampoo provided

TowelsYes

Towels available to rent or borrow

Rest AreaYes

Relaxation space for after bathing

ParkingYes

On-site or nearby parking available

かごの湯温泉

Kago no Yu Onsen

Operated by · 株式会社白浜館

塩

Chloride

+ Bicarbonate

Color: Colorless and clear
Taste: Faintly salty
Odor: Odorless

Sodium Chloride-Bicarbonate spring

pH 7.1Weakly alkalineHot source · 61°CHigh silica

Composition fingerprint4.9 g/kg dissolved · Hypotonic

Na⁺88

Cl⁻55

HCO₃⁻44

◀ CationsAnions ▶

Sodium Na⁺: salt's cation — pairs with chloride to make the water salty.
Chloride Cl⁻: table-salt anion — coats the skin and holds heat in.

Known good for

Warmingcold sensitivity
Aches & jointsstiff shoulders
Smooth skindry, rough skin

A sodium-led chloride / bicarbonate hot spring (60.5 °C wellhead, hypotonic, weakly alkaline). The water is colorless and clear with only a faint salty edge — gentle and warming rather than aggressive on the skin. A generous 117.6 mg/kg of metasilicic acid leaves the kind of silica film that puts this water in the Japanese 'beauty-water' (bihada-no-yu) family, with bicarbonate adding a soft, slick finish on top of the chloride heat-retention.

Sampled at wellhead·Analyzed Feb 16, 2017·一般社団法人和歌山県薬剤師会·Cert no. 第E1702192号

Explore the water

Views

Sea

Highlights

Ganbanyoku

Foot Bath

Lukewarm Bath

Programs

About

The bathhouse looks straight out over the Pacific. The open-air bath, Sandan-no-yu (三段の湯), goes deep enough to soak in while standing, split across three depth levels, and is kept flowing fresh rather than recirculated. The main indoor bath, Umi-no-yu (海の湯), adds a hot pool, a cooler pool, a shallow kids' bath, and rotating seasonal baths like mugwort, iris, or yuzu. A second indoor bath, Nami-no-yu (波の湯), is built with easier footing for anyone unsteady on wet tile and looks out over the Pacific too. The water itself is salty and lightly sulfurous, drawn from two different springs on the property. Outside on the terrace there's a 30-meter infinity foot bath facing the sea, plus a barrel sauna and a separately booked private sauna facility, SAUNA HOUSE on, with its own outdoor bath and cold plunge for small groups. Shirahama is one of Japan's three oldest hot spring towns, and this is one of its large modern resort hotels, expanded in 2023 with the pool and sauna additions, open to day visitors as well as overnight guests.

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4.0

2 reviews

from 1 reviewer

Sergey M

1 year ago

627. Shirahama Key Terrace Hotel Seamore, Wakayama (pt.2) ★★ 3. Lower level (outdoor area). 3.1. Stairs down from the indoor area to the outdoor area. In summer it was poorly maintained - lots of cobwebs at the top, and a fair number of spiders and other local insects on the walls. 3.2. Gorgeous view of the bay and observation tower from the outdoor area. Outdoor infinity onsen with two levels - standing and lying down, but the infinity section is narrow. Clear water with small white mineral fragments. A few small insects and a dead crab in the water. 41 degrees. Cool place, highly recommended for a visit. If the outdoor area were better maintained and the infinity section wider, I'd rate it even higher. 17.06.2025

Sergey M

1 year ago

627. Shirahama Key Terrace Hotel Seamore, Wakayama (pt.1) ★★ Higaeri for 1000. At the main reception there was a Russian-speaking staff member - they sent me downstairs for the onsen payment. Higaeri stated as 13:00 to 20:00. Part of the Shirahama tegata (2 stickers). They sell the 12 Onsen of Wakayama stamp. They issue Toreco cards for the onsen. 1. Upper level (indoor area). Bath with clear water, 41 degrees. Stuffy inside. 2. Middle level (indoor area). View of the bay through glass. Breathable inside. 2.1. Large bath with clear water, 41 degrees. 2.2. Small bath with clear water, 41 degrees. 2.3. Three barrels with clear water, 39 degrees. 2.4. Round hot shallow bath. 2.5. Seated spots with constantly flowing water. 2.6. Sauna. 2.7. Stone bath. 2.8. Cold bath. 17.06.2025