La Sirena Verde is a Spanish restaurant located on Gran Vía Street in Madrid City. The restaurant offers a variety of dishes, including oysters, paella, Galician stews, and seafood. The restaurant has a chic and modern atmosphere, with street tables available for outdoor dining. The staff is friendly and attentive, with some clients praising the excellent service and others complaining about the slow service and lack of attention.The restaurant offers a wide range of payment options, including NFC mobile payments, debit cards, and credit cards. They also accept reservations and have a private dining room available. The restaurant is wheelchair-accessible, with a wheelchair-accessible toilet, seating, and entrance.The restaurant has received mixed reviews from clients, with some praising the quality of the food and others complaining about the high prices and poor service. Some clients have praised the great wine list, great dessert, and great coffee, while others have complained about the expensive paella and the slow service.The restaurant is popular for solo dining, dinner, and lunch, and has a high rating of 4.1 on third-party ratings. The restaurant is open from 7:00 AM to 12:00 AM, Monday to Thursday, and from 8:00 AM to 12:00 AM on Friday to Sunday.Overall, La Sirena Verde is a good option for those looking for a Spanish restaurant with a modern atmosphere and a wide range of dishes. However, clients should be aware that the prices can be high and the service may be slow at times.One notable issue is that some clients have complained about the slow service and the lack of attention from the staff. This is a concern for clients who value good service and a quick dining experience.