Welcome to Riverwalk OBGYN

Overall patient rating:

In 1979 Tristan Castaneda, MD started with a simple premise: Make available to every woman the health resources she needs to live a healthy, active, and long life. At the same time, educate each woman about the importance of preventative health measures. This same idea still drives us today, some 30 years later. The track record we’ve accumulated over the years speaks to our commitment to patients, their families, and the community at large. Both our medical and office staffs are second to none, who genuinely take an interest in individual patient’s needs. We think you’ll notice the difference immediately when you step foot inside our doors. We’d love to see you today to map out a health and wellness plan that’s tailored to your health history and needs.

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About Our Practice

  • Providers

  • Services

  • Links And Forms

  • Locations

  • Contact Us

  • Alka Arya Degaetano

  • Ricardo Munoz

  • Stephanie Schaefer

  • Christina Simpson

  • Heather Williams


We Provide The Following Services

  • Obstetrics + Reproduction
  • Pregnancy Care and Delivery
  • Contraception
  • Ultrasound and Imaging
  • Gynecology + Wellness
  • Annual Exams
  • Menopause
  • Urogynecology

Riverwalk OBGYN: San Antonio Office

  • Monday: 8:30AM - 5:30PM
  • Tuesday: 8:30AM - 5:30PM
  • Wednesday: 8:30AM - 5:30PM
  • Thursday: 8:30AM - 5:30PM
  • Friday: 8:30AM - 5:30PM

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    Patient Reviews

    Overall patient rating for Riverwalk OBGYN:

    Annual Well Woman Exam

    The manner in which Dr. Muñoz treated me was very welcoming and profrssional.

    Pap Smear

    Very friendly

    Annual Well Woman Exam

    Dr Munoz is incredible

    Annual Well Woman Exam

    Dr is always thorough and makes sure you understand what is going on.

    Pelvic Pain

    Dr Simpson is very personable & I feel very comfortable with her & her expertise. Dr Simpson is great gynecologist.

    Gynecological Exams

    The staff made me feel so comfortable during a time of worry.

    Annual Well Woman Exam

    Dr Schaefer is great! The pelvic exam/pap is quick and easy and no more uncomfortable than necessary. She explains everything and listens and addresses my concerns that have been dismissed by other doctors in the past.


    Dr Munoz has been my OBGYN for over 21 years and he is friendly, patient and understanding. He takes the time to listen to his patients and answer all questions....not many Drs do that these days but Dr Munoz cares about his patients amd staff.


    Doctor Arya was so nice, clear, and patient showing us our baby and giving such important information about the pregnancy and delivery.

    Pap Smear

    Dr. Simpson always listens to my needs and concerns. She doesn't make me feel rushed and is always willing to go an extra step to help me get what I need to feel seen.