Yeraltı (Underground) Turkish Series: Plot, Cast, and 2026 Deep-Dive Review

The Turkish television landscape in 2026 has been set ablaze by a single name: Yeraltı. Produced by the legendary Medyapım and airing on NOW TV, this action-drama has quickly transcended being just a “TV show” to become a cultural phenomenon. If you are searching for the yeralti turkish series, you are looking at the most ambitious project of the year, featuring an ensemble cast that defines the new era of Turkish cinema.

In this extensive guide, we will break down the complex alliances, the star-studded cast led by Deniz Can Aktaş, Devrim Özkan, and Uraz Kaygılaroğlu, and everything international fans need to know.

What is Yeraltı About? (The Plot)

Yeraltı (Underground) is a masterful blend of crime, justice, and heartbreaking romance. The story doesn’t just stay on the surface of Istanbul’s criminal world; it digs deep into the psychological toll of living a double life.

The Return of Haydar Ali

The heart of the story is Haydar Ali Aslan (Deniz Can Aktaş). After growing up abroad under the shadow of his family’s tragic past, Haydar Ali is a man of few words but lethal actions. He returns to Istanbul with a singular mission, but a fateful night changes everything. On the very day he proposes to the love of his life, Ceylan (Devrim Özkan), he is forced to kill his father’s murderer, Bedrettin Hanoğlu. This act of vengeance triggers a chain reaction that lands him in prison and eventually into the depths of the “Underground.”

The Mafia and the State

The series takes a sharp turn when Haydar Ali is recruited by Yılmaz Doğan (Mehmet Yılmaz Ak), a high-ranking intelligence officer. Haydar Ali’s task? To infiltrate the “Istanbul Cartel” and gain the trust of its most unpredictable leader, Bozkurt Hanoğlu (Uraz Kaygılaroğlu), also known as “Bozo.”

The tension lies in the shifting loyalties. As Haydar Ali climbs the ranks of the criminal world, he finds himself caught between his duty to the state, his growing respect for Bozo’s code of honor, and his unbreakable love for Ceylan—who is now inextricably linked to the very world he is trying to dismantle.

Meet the Heavyweights: Yeraltı Lead Cast & Characters

One of the reasons the yeralti turkish series has maintained its top spot in the ratings is its incredible cast. Each actor brings a level of intensity that makes every “bolum” (episode) feel like a feature film.

1. Deniz Can Aktaş (as Haydar Ali Aslan)

Deniz Can Aktaş has moved away from his “romantic lead” roots to deliver a raw, physical performance.

• Birth Date: July 28, 1993

• Hometown: Istanbul, Turkey (of Kastamonu descent)

• Education: Graduate of Piri Reis University, Ship Machinery and Management Engineering.

• Career Highlights: Before his breakout in Yeraltı, he gained a massive following in series like Avlu (The Yard), Aşk Ağlatır, and the highly acclaimed Hudutsuz Sevda. His portrayal of Haydar Ali showcases a darker, more complex side of his acting range.

• Instagram: @denizcanaktasofficial

• The Character: Haydar Ali is a specialist in close combat and a strategic genius. He is the bridge between the law and the lawless.

• Why Fans Love Him: Aktaş portrays the internal conflict of a man who must act like a monster to serve the “greater good.”

2. Devrim Özkan (as Halide Ceylan)

Devrim Özkan plays Ceylan, a woman whose life was shattered the moment Haydar Ali went to prison.

• Birth Date: September 2, 1998
• Hometown: Muğla, Turkey
• Education: Studied at Muğla Sıtkı Koçman University, Faculty of Fine Arts (Department of Performing Arts).
• Career Highlights: Known for her strong characters in Vuslat and Ramo, she achieved global stardom with her lead role in Gelsin Hayat Bildiği Gibi. In Yeraltı, she masterfully balances the vulnerability of a lover with the resilience of a woman surviving the mafia world.
• Instagram: @devrimozkan
• The Character: She isn’t just a love interest. Ceylan is a survivor who becomes a pivotal player in the conflict between the Aslan and Hanoğlu families.
• The Chemistry: The “tragic lovers” dynamic between Devrim and Deniz Can is the emotional anchor of the series.

Devrim Özkan is breathtaking as Ceylan, a survivor navigating the chaotic world of the Hanoğlu family in Yeraltı.

3. Uraz Kaygılaroğlu (as Bozkurt “Bozo” Hanoğlu)

Uraz Kaygılaroğlu steals every scene as the charismatic yet dangerous mafia leader, Bozo.

• Birth Date: June 30, 1987
• Hometown: Istanbul, Turkey
• Education: Graduate of Istanbul Bilgi University, Department of Advertising.
• Career Highlights: A true chameleon, Uraz has conquered everything from comedy to heavy drama. His iconic role as Gediz in Sefirin Kızı and his lead in Üç Kuruş paved the way for his portrayal of Bozo—a character defined by a strict honor code and unpredictable flair.
• His Instagram: @urazka
• The Character: Bozo is a man of principles. He hates the chaos his uncle Bedrettin created and seeks to bring a new “order” to the underground.
• The Dynamic: His complex friendship with Haydar Ali is one of the most talked-about aspects of the show on social media.

4. Sümeyye Aydoğan (as Sultan Hanoğlu)

Sümeyye Aydoğan plays Bozo’s sister, Sultan.

• Birth Year: 1999
• Hometown: Istanbul, Turkey
• Career Highlights: She quickly rose to fame with her roles in Duy Beni and Dönence. In the yeralti turkish series, she steps into a more mature and strategic role as the sister of a crime lord, managing the family’s empire with a sharp mind.
• Her Instagram: @sumeyyeaydogan_
• The Character: Far from being a background character, Sultan manages the family’s finances and is fiercely loyal to her brother. Her forced engagement to Haydar Ali (to seal a mafia alliance) creates one of the show’s most intense subplots.

5. Mehmet Yılmaz Ak (as Yılmaz Doğan)

Following his massive success in Yargı, Mehmet Yılmaz Ak returns as the brilliant intelligence chief. He represents the “chess player” who moves the pieces from behind the scenes.

• Birth Date: February 8, 1986
• Hometown: Diyarbakır, Turkey
• Education: Graduate of Kadir Has University, Theater Department.
• Career Highlights: While he has appeared in numerous projects like İçerde and Çukur, he became a household name globally as Savcı Pars in the hit series Yargı (Family Secrets). In Yeraltı, he once again demonstrates his ability to play a brilliant man who is always three steps ahead of everyone else.
• His Instagram: @mehmetyilmazak

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Deep-Dive Review: Why is Yeraltı the Biggest Hit of 2026?

1. The Raci Şaşmaz Influence

With the legendary Raci Şaşmaz (the mind behind Kurtlar Vadisi also known as Valley of Wolfs) involved in the story and design, Yeraltı carries a certain “DNA” of classic Turkish crime dramas but updated with 2026 production values. The dialogue is sharp, and the political undertones are sophisticated.

2. Neon-Noir Cinematography

Directed by Murat Öztürk, the series uses the lights of Istanbul to create a “Neon-Noir” atmosphere. The contrast between the cold, sterile rooms of the intelligence agency and the warm, dangerous gold-and-red hues of the Hanoğlu mansion is visually stunning.

3. Moral Ambiguity

There are no clean-cut heroes in Yeraltı. Even the “good guys” commit crimes, and the “villains” often show more loyalty than the state officials. This gray area keeps the audience constantly debating on platforms like X (Twitter) and Reddit.